"My hunch is when it comes time to polish and fine tune all the moving parts, this process will remain much faster to do by hand"

Depends if what you want to do is new, or has been done a thousand times before

"Describing without words: An artist with a vision can only bring that vision to life with body movements. It is not possible to communicate all the details that go into a great piece of art with words. The colors, lines, shapes, positioning, specific emotions, history... is beyond spoken language."

And you absolutely can use sketches, pictures, drawings as input to the AI.

So in general I agree, at least right now it needs a lot of fine tuning. About the future I make no prophecy, I did not see AI coming this way, so why would I be right about AI in the future now.

I am making a novel game right now with heavy help from Fable and it is awesome. Because even though my game is novel - parts of it are not, but standard and I reinvented the wheel way too often before and am glad don't have to do that anymore.