This needs to be removed:

https://github.com/jbossas/jboss-eap8/blob/8.0.0.Beta/ee-feature-pack/galleon-common/src/main/resources/layers/standalone/management/layer-spec.xml#L9-L11

This was removed upstream in https://github.com/wildfly/wildfly-core/pull/4888 (see discussion on https://github.com/wildfly/wildfly/pull/14986 for background), but pending resolution of JBEAP-19950 in wildfly-to-product this file is being overridden, and the override doesn't have the removal.