The legacy feature pack licenses.xml generation uses the maven-resources-plugin copy-resources goal to copy the core-feature-pack-licenses.xml file from a custom src location to a custom target location, and then runs the licenses-plugin insert-versions goal, using that target file as both an input and an output of that goal.
The problem is using the -Pjboss-release profile causes those executions to occur in a different order. With -Pjboss-release, the copy-resources happens after the insert-versions, removing all effect of the insert-versions.
There are a couple fixes that come to mind. One is moving the copy-resources from prepare-package phase to prepare-resources. The other is dropping the copy-resources altogether and just directly specifying the src file as the input to the insert-versions.
I think I'll go for the latter as the result seems simpler to understand in the future.