During this maintenance window, on-premise agents in the AWS EU region will connect to the new *.servicebus.windows.net URL. If whitelisting for service bus access is required by your IT organization, best practice is to update your whitelisting rules to include this new service bus URL. Otherwise your agents will revert to polling mode and will not operate on an optimal level.
If you are not using on-premise agents in the AWS EU region, you can ignore this notification.
See this article for more information: https://support.tibco.com/s/article/Service-Bus-URL-change-in-Europe-AWS-Region-for-TIBCO-Cloud-Integration-Connect-and-TIBCO-Scribe-Online