EclipseLink is not shipped with Wildfly also not compatible/tested components with Wildfly.. It is a 3rd party components which can be integrate with Wildfly.
The community documentation shows how to install EclipseLink as a module:
Please list the contents of your ear and/or war/jar files (e.g. show output from "jar tf yourApp.jar"). If you don't want to list the entire contents, that is fine, I'm just curious as to where the persistence.xml file is and where the entity classes are as well, in your deployment.
It is hard to guess as to where the bug is exactly. I'm not sure if the EclipseLink (org.eclipse.persistence.internal.jpa.deployment.ArchiveFactoryImpl) logging would help or if debugging is needed.