Ever seen the game Vaudeville? It's a fairly basic detective game but all the characters have their own LLM and AI voices. I bought it for the reason you described. I just had to see the technology in action and I can definitely see a future with generative text/voices in games.
It's not perfect by any means but I think it's a very cool approach to a detective game. There have been updates to it since I played that address most of the problems I had with it like characters forgetting past conversations and giving conflicting info.