With managed topology when replica is removed:
ipa-server-install --uninstall tells always(if it was connected to other replica) following message:

Replication agreements with the following IPA masters found:
other.example.com. Removing any replication agreements before
uninstalling the server is strongly recommended. You can remove replication
agreements by running the following command on any other IPA master:
$ ipa-replica-manage del this.example.com

This message is displayed even after the ipa-replica-manage del this.example.com command is executed. It's because it no-longer removes the agreements but rather disallows the old replica to connect to remaining replicas.

The check should be reworked or removed(with proper replacement).