diff --git a/.gitlab/ci/build-images.gitlab-ci.yml b/.gitlab/ci/build-images.gitlab-ci.yml
index 10b8d19e0db3dbdb748897454bec2409078d1c64..dbd956214dd5367c0850dbbb000766d1414669e5 100644
--- a/.gitlab/ci/build-images.gitlab-ci.yml
+++ b/.gitlab/ci/build-images.gitlab-ci.yml
@@ -2,8 +2,6 @@
   extends: .use-kaniko
   variables:
     GIT_LFS_SKIP_SMUDGE: 1
-  script:
-    - scripts/checkout-mr-source-sha
   retry: 2
 
 # This image is used by:
@@ -20,8 +18,7 @@ build-qa-image:
     # Default latest tag for particular branch
     QA_IMAGE_BRANCH: ${CI_REGISTRY}/${CI_PROJECT_PATH}/gitlab-ee-qa:${CI_COMMIT_REF_SLUG}
   script:
-    - !reference [.base-image-build, script]
-    - export QA_IMAGE="${CI_REGISTRY}/${CI_PROJECT_PATH}/gitlab-ee-qa:${CI_MERGE_REQUEST_SOURCE_BRANCH_SHA:-$CI_COMMIT_SHA}"
+    - export QA_IMAGE="${CI_REGISTRY}/${CI_PROJECT_PATH}/gitlab-ee-qa:${CI_COMMIT_SHA}"
     - echo $QA_IMAGE
     - echo $QA_IMAGE_BRANCH
     - |
@@ -45,7 +42,6 @@ build-assets-image:
   stage: build-images
   needs: ["compile-production-assets"]
   script:
-    - !reference [.base-image-build, script]
     # TODO: Change the image tag to be the MD5 of assets files and skip image building if the image exists
     # We'll also need to pass GITLAB_ASSETS_TAG to the trigerred omnibus-gitlab pipeline similarly to how we do it for trigerred CNG pipelines
     # https://gitlab.com/gitlab-org/gitlab/issues/208389
diff --git a/.gitlab/ci/frontend.gitlab-ci.yml b/.gitlab/ci/frontend.gitlab-ci.yml
index 4298482e03d27be8bff0e0c3e555e235985019e8..59a144b952dd3b4ef5e3ce6fbd365eb8d473d6a6 100644
--- a/.gitlab/ci/frontend.gitlab-ci.yml
+++ b/.gitlab/ci/frontend.gitlab-ci.yml
@@ -43,7 +43,6 @@ compile-production-assets:
       - webpack-report/
     when: always
   before_script:
-    - scripts/checkout-mr-source-sha
     - !reference [.default-before_script, before_script]
   after_script:
     - rm -f /etc/apt/sources.list.d/google*.list  # We don't need to update Chrome here
diff --git a/.gitlab/ci/review-apps/qa.gitlab-ci.yml b/.gitlab/ci/review-apps/qa.gitlab-ci.yml
index 54f9b1839191bddf14422ae683833af2803b20f6..e664e55606812000289d8f75672d838a404e7d04 100644
--- a/.gitlab/ci/review-apps/qa.gitlab-ci.yml
+++ b/.gitlab/ci/review-apps/qa.gitlab-ci.yml
@@ -42,7 +42,6 @@ include:
     GIT_LFS_SKIP_SMUDGE: 1
     WD_INSTALL_DIR: /usr/local/bin
   before_script:
-    - scripts/checkout-mr-source-sha
     - !reference [.bundle-base, before_script]
   script:
     - export EE_LICENSE="$(cat $REVIEW_APPS_EE_LICENSE_FILE)"
@@ -61,7 +60,7 @@ include:
         --format RspecJunitFormatter --out tmp/rspec.xml \
       ]" || qa_run_status=$?
     - if [ ${qa_run_status} -ne 0 ]; then
-        release_sha=$(echo "${CI_MERGE_REQUEST_SOURCE_BRANCH_SHA:-${CI_COMMIT_SHA}}" | cut -c1-11);
+        release_sha=$(echo "${CI_COMMIT_SHA}" | cut -c1-11);
         echo "Errors can be found at https://sentry.gitlab.net/gitlab/gitlab-review-apps/releases/${release_sha}/all-events/.";
       fi
     - exit ${qa_run_status}
diff --git a/doc/development/testing_guide/end_to_end/index.md b/doc/development/testing_guide/end_to_end/index.md
index 0eb7f0645bd027e0638c0bdc25fb395948f50d12..40d610cfffcb4c44a407f9be614d42f343049eae 100644
--- a/doc/development/testing_guide/end_to_end/index.md
+++ b/doc/development/testing_guide/end_to_end/index.md
@@ -100,22 +100,19 @@ A feature proposal to segregate access control regarding running pipelines from
 #### With merged results pipelines
 
 In a merged results pipeline, the pipeline runs on a new ref that contains the merge result of the source and target branch.
-However, this ref is not available to the `gitlab-qa-mirror` pipeline.
 
-For this reason, the end-to-end tests on a merged results pipeline would use the head of the merge request source branch.
+The end-to-end tests on a merged results pipeline would use the new ref instead of the head of the merge request source branch.
 
 ```mermaid
 graph LR
 
-A["a1b1c1 - branch HEAD (CI_MERGE_REQUEST_SOURCE_BRANCH_SHA)"]
-B["x1y1z1 - master HEAD"]
-C["d1e1f1 - merged results (CI_COMMIT_SHA)"]
+A["x1y1z1 - master HEAD"]
+B["d1e1f1 - merged results (CI_COMMIT_SHA)"]
 
-A --> C
-B --> C
+A --> B
 
-A --> E["E2E tests"]
-C --> D["Merged results pipeline"]
+B --> C["Merged results pipeline"]
+C --> D["E2E tests"]
  ```
 
 ##### Running custom tests
diff --git a/scripts/build_assets_image b/scripts/build_assets_image
index 60bd9190b7427f99885ef4fc91345176b7f9a135..8aa6526061adaca9eeb3ce7e3369b389839c4490 100755
--- a/scripts/build_assets_image
+++ b/scripts/build_assets_image
@@ -19,12 +19,8 @@ cp -r public/assets assets_container.build/public/
 cp Dockerfile.assets assets_container.build/
 
 COMMIT_REF_SLUG_DESTINATION=${ASSETS_IMAGE_PATH}:${CI_COMMIT_REF_SLUG}
-# Use CI_MERGE_REQUEST_SOURCE_BRANCH_SHA (MR HEAD commit) so that the image is in sync with Omnibus/CNG images.
-# Background: Due to the fact that we cannot retrieve the Merged Commit in the downstream omnibus/CNG pipelines,
-# we're building the Omnibus/CNG images for the MR HEAD commit.
-# In turn, the assets image also needs to be built from the MR HEAD commit, so that everything is build from the same commit.
-# For non-MR commits, we fallback to $CI_COMMIT_SHA.
-COMMIT_SHA_DESTINATION=${ASSETS_IMAGE_PATH}:${CI_MERGE_REQUEST_SOURCE_BRANCH_SHA:-$CI_COMMIT_SHA}
+
+COMMIT_SHA_DESTINATION=${ASSETS_IMAGE_PATH}:${CI_COMMIT_SHA}
 COMMIT_REF_NAME_DESTINATION=${ASSETS_IMAGE_PATH}:${CI_COMMIT_REF_NAME}
 
 DESTINATIONS="--destination=$COMMIT_REF_SLUG_DESTINATION --destination=$COMMIT_SHA_DESTINATION"
diff --git a/scripts/checkout-mr-source-sha b/scripts/checkout-mr-source-sha
deleted file mode 100755
index 962e3f1348ded0a765611d94a51907cabd637a2d..0000000000000000000000000000000000000000
--- a/scripts/checkout-mr-source-sha
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/sh
-
-if [ -n "$CI_MERGE_REQUEST_SOURCE_BRANCH_SHA" ]; then
-  echo "Checking out \$CI_MERGE_REQUEST_SOURCE_BRANCH_SHA ($CI_MERGE_REQUEST_SOURCE_BRANCH_SHA) instead of \$CI_COMMIT_SHA (merge result commit $CI_COMMIT_SHA) so that code is in sync with gitlab images built upstream."
-  echo "See https://docs.gitlab.com/ee/development/testing_guide/end_to_end/index.html#with-pipeline-for-merged-results for more details."
-  git checkout -f ${CI_MERGE_REQUEST_SOURCE_BRANCH_SHA}
-fi
diff --git a/scripts/generate-e2e-pipeline b/scripts/generate-e2e-pipeline
index 0588b923b3b8542523f2374f5d43de80c7fdfa7e..b6519eff621619192df956d40a850cdce0a35634 100755
--- a/scripts/generate-e2e-pipeline
+++ b/scripts/generate-e2e-pipeline
@@ -15,7 +15,7 @@ fi
 
 variables=$(cat <<YML
 variables:
-  RELEASE: "${CI_REGISTRY}/gitlab-org/build/omnibus-gitlab-mirror/gitlab-ee:${CI_MERGE_REQUEST_SOURCE_BRANCH_SHA:-$CI_COMMIT_SHA}"
+  RELEASE: "${CI_REGISTRY}/gitlab-org/build/omnibus-gitlab-mirror/gitlab-ee:${CI_COMMIT_SHA}"
   SKIP_REPORT_IN_ISSUES: "${SKIP_REPORT_IN_ISSUES:-true}"
   OMNIBUS_GITLAB_CACHE_UPDATE: "${OMNIBUS_GITLAB_CACHE_UPDATE:-false}"
   COLORIZED_LOGS: "true"
diff --git a/scripts/trigger-build.rb b/scripts/trigger-build.rb
index 03d789e5dae235ff35da0c0efb370b2f18cc87bb..75f3967cb4a26a5b027aab16415921ad617288a2 100755
--- a/scripts/trigger-build.rb
+++ b/scripts/trigger-build.rb
@@ -144,12 +144,10 @@ def ref
     end
 
     def base_variables
-      # Use CI_MERGE_REQUEST_SOURCE_BRANCH_SHA for omnibus checkouts due to pipeline for merged results,
-      # and fallback to CI_COMMIT_SHA for the `detached` pipelines.
       {
         'GITLAB_REF_SLUG' => ENV['CI_COMMIT_TAG'] ? ENV['CI_COMMIT_REF_NAME'] : ENV['CI_COMMIT_REF_SLUG'],
         'TRIGGERED_USER' => ENV['TRIGGERED_USER'] || ENV['GITLAB_USER_NAME'],
-        'TOP_UPSTREAM_SOURCE_SHA' => Trigger.non_empty_variable_value('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA') || ENV['CI_COMMIT_SHA']
+        'TOP_UPSTREAM_SOURCE_SHA' => ENV['CI_COMMIT_SHA']
       }
     end
 
@@ -186,14 +184,9 @@ def trigger_stable_branch_if_detected?
     end
 
     def extra_variables
-      # Use CI_MERGE_REQUEST_SOURCE_BRANCH_SHA (MR HEAD commit) so that the image is in sync with the assets and QA images.
-      # See https://docs.gitlab.com/ee/development/testing_guide/end_to_end/index.html#with-pipeline-for-merged-results.
-      # We also set IMAGE_TAG so the GitLab Docker image is tagged with that SHA.
-      source_sha = Trigger.non_empty_variable_value('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA') || ENV['CI_COMMIT_SHA']
-
       {
-        'GITLAB_VERSION' => source_sha,
-        'IMAGE_TAG' => source_sha,
+        'GITLAB_VERSION' => ENV['CI_COMMIT_SHA'],
+        'IMAGE_TAG' => ENV['CI_COMMIT_SHA'],
         'SKIP_QA_DOCKER' => 'true',
         'SKIP_QA_TEST' => 'true',
         'ALTERNATIVE_SOURCES' => 'true',
@@ -228,14 +221,11 @@ def trigger_stable_branch_if_detected?
     end
 
     def extra_variables
-      # Use CI_MERGE_REQUEST_SOURCE_BRANCH_SHA (MR HEAD commit) so that the image is in sync with the assets and QA images.
-      source_sha = Trigger.non_empty_variable_value('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA') || ENV['CI_COMMIT_SHA']
-
       {
         "TRIGGER_BRANCH" => ref,
-        "GITLAB_VERSION" => source_sha,
+        "GITLAB_VERSION" => ENV['CI_COMMIT_SHA'],
         "GITLAB_TAG" => ENV['CI_COMMIT_TAG'], # Always set a value, even an empty string, so that the downstream pipeline can correctly check it.
-        "GITLAB_ASSETS_TAG" => ENV['CI_COMMIT_TAG'] ? ENV['CI_COMMIT_REF_NAME'] : source_sha,
+        "GITLAB_ASSETS_TAG" => ENV['CI_COMMIT_TAG'] ? ENV['CI_COMMIT_REF_NAME'] : ENV['CI_COMMIT_SHA'],
         "FORCE_RAILS_IMAGE_BUILDS" => 'true',
         "CE_PIPELINE" => Trigger.ee? ? nil : "true", # Always set a value, even an empty string, so that the downstream pipeline can correctly check it.
         "EE_PIPELINE" => Trigger.ee? ? "true" : nil # Always set a value, even an empty string, so that the downstream pipeline can correctly check it.
@@ -399,9 +389,7 @@ def downstream_project_path
 
     def extra_variables
       {
-        # Use CI_MERGE_REQUEST_SOURCE_BRANCH_SHA for omnibus checkouts due to pipeline for merged results
-        # and fallback to CI_COMMIT_SHA for the `detached` pipelines.
-        'GITLAB_COMMIT_SHA' => Trigger.non_empty_variable_value('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA') || ENV['CI_COMMIT_SHA'],
+        'GITLAB_COMMIT_SHA' => ENV['CI_COMMIT_SHA'],
         'TRIGGERED_USER_LOGIN' => ENV['GITLAB_USER_LOGIN']
       }
     end
diff --git a/spec/scripts/trigger-build_spec.rb b/spec/scripts/trigger-build_spec.rb
index f42a728e62462ce28af728109b4319b0e0e46ac3..114746c714d8a03f2c33ea7ac54892f5a09357e6 100644
--- a/spec/scripts/trigger-build_spec.rb
+++ b/spec/scripts/trigger-build_spec.rb
@@ -195,33 +195,13 @@ def ref_param_name
           end
         end
 
-        context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is set' do
+        context 'when CI_COMMIT_SHA is set' do
           before do
-            stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', 'ci_merge_request_source_branch_sha')
-          end
-
-          it 'sets TOP_UPSTREAM_SOURCE_SHA to ci_merge_request_source_branch_sha' do
-            expect(subject.variables['TOP_UPSTREAM_SOURCE_SHA']).to eq('ci_merge_request_source_branch_sha')
-          end
-        end
-
-        context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is set as empty' do
-          before do
-            stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', '')
-          end
-
-          it 'sets TOP_UPSTREAM_SOURCE_SHA to CI_COMMIT_SHA' do
-            expect(subject.variables['TOP_UPSTREAM_SOURCE_SHA']).to eq(env['CI_COMMIT_SHA'])
-          end
-        end
-
-        context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is not set' do
-          before do
-            stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', nil)
+            stub_env('CI_COMMIT_SHA', 'ci_commit_sha')
           end
 
           it 'sets TOP_UPSTREAM_SOURCE_SHA to CI_COMMIT_SHA' do
-            expect(subject.variables['TOP_UPSTREAM_SOURCE_SHA']).to eq(env['CI_COMMIT_SHA'])
+            expect(subject.variables['TOP_UPSTREAM_SOURCE_SHA']).to eq('ci_commit_sha')
           end
         end
       end
@@ -275,41 +255,15 @@ def ref_param_name
         )
       end
 
-      context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is set' do
-        before do
-          stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', 'ci_merge_request_source_branch_sha')
-        end
-
-        it 'sets GITLAB_VERSION & IMAGE_TAG to ci_merge_request_source_branch_sha' do
-          expect(subject.variables).to include(
-            'GITLAB_VERSION' => 'ci_merge_request_source_branch_sha',
-            'IMAGE_TAG' => 'ci_merge_request_source_branch_sha'
-          )
-        end
-      end
-
-      context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is set as empty' do
+      context 'when CI_COMMIT_SHA is set' do
         before do
-          stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', '')
+          stub_env('CI_COMMIT_SHA', 'ci_commit_sha')
         end
 
-        it 'sets GITLAB_VERSION & IMAGE_TAG to CI_COMMIT_SHA' do
+        it 'sets GITLAB_VERSION & IMAGE_TAG to ci_commit_sha' do
           expect(subject.variables).to include(
-            'GITLAB_VERSION' => env['CI_COMMIT_SHA'],
-            'IMAGE_TAG' => env['CI_COMMIT_SHA']
-          )
-        end
-      end
-
-      context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is not set' do
-        before do
-          stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', nil)
-        end
-
-        it 'sets GITLAB_VERSION & IMAGE_TAG to CI_COMMIT_SHA' do
-          expect(subject.variables).to include(
-            'GITLAB_VERSION' => env['CI_COMMIT_SHA'],
-            'IMAGE_TAG' => env['CI_COMMIT_SHA']
+            'GITLAB_VERSION' => 'ci_commit_sha',
+            'IMAGE_TAG' => 'ci_commit_sha'
           )
         end
       end
@@ -483,33 +437,13 @@ def ref_param_name
       end
 
       describe "GITLAB_VERSION" do
-        context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is set' do
-          before do
-            stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', 'ci_merge_request_source_branch_sha')
-          end
-
-          it 'sets GITLAB_VERSION to CI_MERGE_REQUEST_SOURCE_BRANCH_SHA' do
-            expect(subject.variables['GITLAB_VERSION']).to eq('ci_merge_request_source_branch_sha')
-          end
-        end
-
-        context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is set as empty' do
-          before do
-            stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', '')
-          end
-
-          it 'sets GITLAB_VERSION to CI_COMMIT_SHA' do
-            expect(subject.variables['GITLAB_VERSION']).to eq(env['CI_COMMIT_SHA'])
-          end
-        end
-
-        context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is not set' do
+        context 'when CI_COMMIT_SHA is set' do
           before do
-            stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', nil)
+            stub_env('CI_COMMIT_SHA', 'ci_commit_sha')
           end
 
           it 'sets GITLAB_VERSION to CI_COMMIT_SHA' do
-            expect(subject.variables['GITLAB_VERSION']).to eq(env['CI_COMMIT_SHA'])
+            expect(subject.variables['GITLAB_VERSION']).to eq('ci_commit_sha')
           end
         end
       end
@@ -547,10 +481,9 @@ def ref_param_name
           end
         end
 
-        context 'when CI_COMMIT_TAG and CI_MERGE_REQUEST_SOURCE_BRANCH_SHA are nil' do
+        context 'when CI_COMMIT_TAG is nil' do
           before do
             stub_env('CI_COMMIT_TAG', nil)
-            stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', nil)
           end
 
           it 'sets GITLAB_ASSETS_TAG to CI_COMMIT_SHA' do
@@ -829,33 +762,13 @@ def ref_param_name
       end
 
       describe "GITLAB_COMMIT_SHA" do
-        context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is set' do
-          before do
-            stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', 'ci_merge_request_source_branch_sha')
-          end
-
-          it 'sets GITLAB_COMMIT_SHA to ci_merge_request_source_branch_sha' do
-            expect(subject.variables['GITLAB_COMMIT_SHA']).to eq('ci_merge_request_source_branch_sha')
-          end
-        end
-
-        context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is set as empty' do
-          before do
-            stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', '')
-          end
-
-          it 'sets GITLAB_COMMIT_SHA to CI_COMMIT_SHA' do
-            expect(subject.variables['GITLAB_COMMIT_SHA']).to eq(env['CI_COMMIT_SHA'])
-          end
-        end
-
-        context 'when CI_MERGE_REQUEST_SOURCE_BRANCH_SHA is not set' do
+        context 'when CI_COMMIT_SHA is set' do
           before do
-            stub_env('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA', nil)
+            stub_env('CI_COMMIT_SHA', 'ci_commit_sha')
           end
 
-          it 'sets GITLAB_COMMIT_SHA to CI_COMMIT_SHA' do
-            expect(subject.variables['GITLAB_COMMIT_SHA']).to eq(env['CI_COMMIT_SHA'])
+          it 'sets GITLAB_COMMIT_SHA to ci_commit_sha' do
+            expect(subject.variables['GITLAB_COMMIT_SHA']).to eq('ci_commit_sha')
           end
         end
       end