Lol I was just saying it was confirmed on stream which is more reliable than the two and fro on here. I have not played cannon with the new book so can't comment o rest.
They tear units over 5 apart from my 2 games with them so far. Not bad either against under 5. And hard to shift ignoring rend and benefiting from gravesites, DI, and lantern spell if you have it. Then if removed can just re-summon. The 2" reach and 8" fly is good too.
I'd like to know this too. Most allegiance abilities have the faction keyword, these do not. I would assume it's a no though but I think it says in core rules that allies cannot benefit regardless (don't have it to hand).