It's definitely not WAD in the literal sense, but it's WAD insofar as vanilla behavior. We don't have any non-vanilla effect upon anti-popes, aside from the current HIP release lacking the depose_antipope CB and the Anti-King faction for deposing antipopes and the king that set them up in the first place in one go. [All those are included in the next release, BTW.]I am reposting this since it has not yet been responded to.
CKII weirdness, what can I say?