To write a piece of music, you're working at so many different levels, the analytical, emotional, and structural as well as drawing on years of training and experience. When a person with little (or even just a moderate amount of) music training generates a piece of music in a couple hours, are they actually a composer? I personally would say no. I mean it does take a good ear (which is important) to use a music generator well, but still, would say they are more of an editor or an evaluator or a practical critic of music instead of a composer.
Yeah, at what point in a discipline does the increasing skill of AI overtake the need for our contributions from the working being done? In music, it's happened already. Looks like it's happening in coding too.