What if a third-party could subscribe to status updates to a credential? For example, if a manager requires their team to have specific credentials, but those credentials expire after a certain period, can that manager subscribe to a credential so that they get email notifications when it expires? That way, they know their team member needs to retrain/ is no longer fully credentialed.

IMO, it's worth having notifications for expirations, re-issuance and deletions.