This statement is confusing. You don't necessarily want a party size to be limited and you don't want to make a hard call about who's going to continue on that adventure with you, but you recognize the value of a more intimate group? I can't tell from this comment if you're just willing to deal with whatever they decide to do, or if a smaller party size justified by an intense narrative shift is a dealbreaker for you.
I can recognize that in certain games it works. I don't think it's appropriate for a BG game. Could the game still be fun? Yes, but in a way that doesn't quite scratch the itch that I have for a BG game. Overall, I suppose I'm willing to deal at this point.
I also don't have a problem with making "hard calls" - that's what the party dynamic in BG was sometimes about. I don't like how it's being done here though. It removes a lot of interesting characterization that could potentially occur. I also wouldn't call it a dealbreaker - it just isn't consistent with the underlying design philosophy of the previous games.
As you've said, I think that we are still very much in a "wait-and-see" sort of situation.
