Update temporal-nexus.mdx

Author: stephanos

docs/production-deployment/self-hosted-guide/temporal-nexus.mdx

@@ -156,11 +156,3 @@ sequenceDiagram
 ```
 
 Callbacks are delivered to the caller Namespace's active Cluster, re-resolved on each attempt.
-
-:::note Abrupt region loss
-
-Replication is asynchronous, so state not replicated before the loss is lost. A
-Namespace still active on the lost Cluster resumes once it's failed over to a
-surviving Cluster.
-
-:::