It’s already being done and a ton of companies are offering it as a service.

Main thing is the development cycle. Large games can take 5+ years. So to see something at this level of ai for a large scale game maybe 5 years. But you will already be seeing them in small and indie games. Additionally the transformer and chat gtp have already been out a wild(we are on version 4) so it probably won’t take 5+ years.