The PR is an upgrade of the webservices stack, including JBossWS, Apache CXF, JAXB-RI and JAXB API. In particular, the JAXB upgrade is for EE8 and better JDK 9 compatibility.
Now, due to the upgrade of the JAXB API spec jar, the PR is essentially stalled since 20 days; the new spec is released as an alpha (as it's been tested within JBossWS only) and that does not satisfy a rule that requires any artifact being pulled to be Final.
We're talking about a spec jar, we could simply re-tag that as Final, chances are we won't need changes any time soon there anyway, but as Tomaz pointed out, in principle that would be dishonest.