Yes, WildFly needs to keep including the current Hibernate ORM  5.1 jar for application compatibility but we also need to include the newer Hibernate ORM 5.3+ jar for EE 8/JPA 2.2 use.  So, we really need a new ORM module, since we will keep both Hibernate versions in WildFly for a while (ORM 5.3 may get swapped out with a newer version later, TBD).

Scott