Alignment changing roles are not in themselves bastard, just difficult to balance.
I think that having the expectation that alignments never change is not warranted, and depends heavily on site meta. It has never been our site meta to have locked-in alignments.
I think the same goes for roles which alter or otherwise manipulate communication from the mods, especially public communication. I think we all accept that role results are subject to manipulation, while it's generally the opinion that things like flips and mod player confirmations should be sacrosanct. I think its more sensible for a mod to specifically say that their games may include such roles, otherwise it gives established players an advantage because they would know host metas - i.e. that Luna includes them but I never do. A new player should not be required to research mod metas to be competitive. That doesn’t mean that they should have to specify that it exists in this particular game, just that its a possibilty that players should be aware of. While this can weaken the usefulness of such a role if it does exist, it also allows the scum team to introduce doubt in mod communications when they know there is no reason for such doubt to exist.
One idea I did have once is for a TP that could modify flips and sow general chaos, it's the only time I was tempted to use this mechanic lol.
Mods should straight up not lie in PMs ever. The possibility of flavored roles (paranoid, insane) should always be disclosed as well. Bastard to me is also about balance and can be a spectrum. I think much more games are accidentally bastard than intentionally.