I really, really hope some of those 'Advanced Specialties' will be Guardsman-esque specialties instead of more non-Guardsman specialties. As is, only 5/12 of the specialties are for Guardsmen. It's like "hey, we can play Imperial Guardsmen now! What do you guys want to play?" "A stormtrooper/tech-priest enginseer/psyker".
I'm not saying Support Specialties are bad, but I hope the book still keeps some focus on playing Imperial Guardsmen.
Atleast there's a homebrew Siege Warfare specialty and Non-Ratling Marksman specialty. I'd like to see FFG do a Not-Adept specialty though. Something focused on the non-combat duties such as signalling and paperwork.
Adding in the Imperial Navy wouldn't really detrac from the theme of Only War, so long as the focus is on Armsmen and Aerospacecraft.
Even then, drop/paratrooper regiments DO make limited use of aircraft that are their own.
The Sabbath crusade is the product of Den Abnett and not GW's.
It 100% is GW's. They own every shred of 40K IP. Dan Abnett wrote it for Black Library. Black Library is part of GW.
Oh, I meant that he is a "real" author and not "just" a fluff/codex-writer, like, he still writes Gaunt's Ghost books, so if GW messes up the Tanith fluff, then they will mess up the whole Gaunt's Ghost line. And that's a big thing, not an oldcrons-newcrons case. And doing it just because FFG wants them in its expansion book is kinda' silly.
How can you forget the Golden 'Everything and Nothing Is Canon' rule!?
And…yeah. The FFG fluff is great, but plenty of people run game set in different sectors, subsectors etc.