Nat,
Thank you for raising it. I have filed a bug for the dev team to investigate about JavaEE 6 project deployment issue on Jonas5.3.
The latest version of TomEE that is supported in MyEclipse 2015 CI is TomEE 1.6. I have raised an enhancement request to support TomEE 1.7.
There is no JBoss 8. Its a new server now,called Wildfly and it is supported in MyEclipse 2015.
Sorry for inconvenience caused. Let us know if you see any issues.