The Apostasy is a civil war...
Maybe the current route of
GW is focused on campaigns with two forces who are known enemies. ( Orks vs
SW.
CSM vs
DA. ) and
BL is supposed to support them.
This will bind a lot of ressources.
I'd hope we get something different, like the Apostasy. But I know it involves Sisters ( a part of the background without strong backup at
GW ) and other Imperials.
The majority of groups involved there has no favor, no one to push them
IMO.