The Warhammer Community site just teased a little bit more about Blackstone Fortress:
“Also landing in time for Christmas will be one of the most anticipated releases of the year land, with Warhammer Quest: Blackstone Fortress. In this new game, you’ll have the chance to dive into one of the 41st Millennium darkest mysteries in thrilling cooperative adventures.
Working with your friends, you’ll choose from a cast of heroes and battle your way to the heart of a Blackstone fortress in search of glory and secrets… (also, monsters).
We’re incredibly excited to share Blackstone Fortress with you guys – this is a roleplaying boardgame of exploration and adventure unlike anything you’ve seen before – and includes some new Warhammer 40,000 models that you will not believe… For now, suffice to say, you should save a space on your Christmas list for this one.
We’ll have more details on all of these releases, and more, for you soon.”
https://www.warhammer-community.com/2018/10/28/christmas-preview-bundles-battleforces-and-boxed-games/