Abaddon returns, can't take Vigilus as it'd cause too many issues.
How's the big bad supposed to win and yet lose as he has too?..
Beacuase in all this chaos hype everyone seems to have completely forgotten that genestealer cult uprisings are the herald for something alot scarier.
The GSC uprising started early because of all the stuff happening on the planet right now though. It's not like the Tyranids are right around the corner this time.