In this case, an exception should be thrown, since there can be at most one process definition receiving a start message with a specific name. This is a regression in 7.2 and work with 7.1.
Reason:
Quite likely has to do with the DbEntityCache and the keys under which a message event subscription created during deployment is put into the cache (cf DbEntityCache, DbEntityCacheKeyMapping and the logic that creates and inserts the MessageEventSubscriptionEntity into the cache)
Not sure if thissue affects version > 7.2.x