Copyright payouts (especially from streaming) are a small fraction, often negligible, of the livelihood of a professional musician. Keep in mind that in a world with free models, anyone could create AI music without silicon valley's involvement. My assumption is that "bad" music would be replaced by AI, while "good" music would not because AI simply wouldn't be able to deliver the goods.

Now, if AI could literally replace every musician, that would obviously be bad. But I don't think that banning it would solve the problem. If society as a whole is so against AI music that banning it is politically popular, it's because they don't like AI music to begin with - nothing to fear, then.