there's no reason for it to not just be some other game set in forgotten realms.

This right here.

The Forgotten Realms is such a fantastic setting in its own right. I'd much rather see it get the exposure it deserves as the rich and historied world that it is. Build a good game(something this studio is quite capable of doing) and then set yourself up to sell the world itself rather than shamelessly pretending to be the next installment of a timeless masterpiece.