I have to say, Fallout 2 had some absolutely crazy levels of reactivity here and there. Just look up "Golden Globes" on a Fallout wiki. Granted, it is unusual even by Fallout standards. It has the hallmarks of one or two people sitting down on extra time and designing an interaction just for the sake of the art. And the end result is that a type of character played by more or less no one because the requirements were to specific had a few extra lines in encounters while walking the town.
The takeaway from this is that no, BG3's reactivity, if it turns out to be as impressive as anticipated, is not a revolution. It's not something that hasn't been done before, except in scope. It is something game studios should've aspired to in the last 25 years, knew how to do, and did not. So really, they do not have a reason to complain.
