Currently, EchoEvent::create returns EchoEvent|false False if aborted via hook or Echo DB is read-only. It should also be able to return a status object to explain why the echo event was aborted via hook
Use case:
T235873: Add variables in Abusefilter to detect/block thanks - there should be a way to pass AbuseFilter warnings/disallow messages to the thanks api when the AbuseFilter aborts the insertion of an event