I’m sure that AI presents some great opportunities (as well as risks) for NPC dialogue in future games, but I don’t see Larian tagging it on at this late stage of BG3 development. I’d be surprised if they divert from the traditionally written/voiced dialogue that we’ve seen in EA.

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"