And you can bet, the AI written song will have a name on the copyright for some human or corporation to rake in the creator's royalties.
I'll take that bet.
Perhaps, someday, AI will become intelligent and be able to show work product but that day is not here.
Here's the thing. If it were to happen, we would not know. Why? If someone were to pull it off and was stupid enough to boast about it, the work would immediately go into the Public Domain. All the services that had paid monies would be able to sue for recovery and they would win.