You could certainly build that today, mario tennis had ai controlled virtual tennis players 20+ years ago. You would simply need to put two of them opposite each other and you could create this. It's just not very compelling to watch two video game npcs do things.

Why not play with actual robots? We did have robots vs robots tournaments before. AI will just make it more interesting.

Maybe they will be optimized out of the gate unlike games nowadays lol. No waiting for dlc.