Perhaps AI will help with procedural generation of environmental details within a pre-built game world. This way the AI isn't burdened with generating the whole scene, but only the clutter of objects and textures - things that usually take a long time to build by hand.

For example in Train or Truck Simulators, I see examples where someone has put effort into making that farmhouse in the distance nicely detailed, but other times it's just a simple structure. If AI were tasked with "distant details", the whole game could look more polished.