The version.txt from a non-manifest build (i.e. just building the 8.1.x branch) has an odd version string:

$ cat version.txt
Red Hat JBoss Enterprise Application Platform - Version 8.1 Update 0.0

 
It's fine with the manifest, which brings in a different wildfly-ee-product-conf artifact, hence the minor priority.

Fixing this would likely require making a change until GA and then changing it again after GA. That's what I had to do in the repo for the external wildfly-ee-product-conf artifact.