Clarify general Geo upgrade note

doc/administration/geo/replication/upgrading_the_geo_sites.md

@@ -26,9 +26,8 @@ Upgrading Geo sites involves performing:
 ## General upgrade steps
 
 NOTE:
-These general upgrade steps are not intended for multi-site deployments,
-and cause downtime. If you want to avoid downtime, consider using
-[zero downtime upgrades](../../../update/zero_downtime.md#multi-node--ha-deployment-with-geo).
+These general upgrade steps require downtime in a multi-node setup.
+If you want to avoid downtime, consider using [zero downtime upgrades](../../../update/zero_downtime.md#multi-node--ha-deployment-with-geo).
 
 To upgrade the Geo sites when a new GitLab version is released, upgrade **primary**
 and all **secondary** sites: