I draw a distinction here from LLMs used for writing code. Plenty of people freely put their code on Github or in Stack Overflow with the expectation that people could freely copy and use it. Relatively little music is shared so permissively.
(And before someone cries "fair use", I'm making an ethical argument, not a legal one. A fair use defense can protect you from a copyright claim, but it doesn't make it any less shitty to take other people's art, blend it all together, and use the result to threaten their livelihoods.)