One thing to note is the fact that this new badgirl Caelar Argent is not mentioned at all in bg2 or in tob. No hell trial. No Abyss Caelar or anything. Ascension mod will now feel weird and people will ask where is Caelar? Why not another dead Bhaalspawn to fight? I hope Beamdog will continue to create content for bg2ee and bridge some story content gaps that are now being created by this interquel. I will say that this early army battle excites me greatly. Kudos to them for that. I've wanted something polished like that for a long time.
I suspect that if they are successful, they will add a new BG2EE expansion related to this story, which would be awesome. Let's hope they are indeed successful, although I suspect they will be.