I think that it will come down to "fair use."

The songs are out there in the world. They were used but not exactly replicated. They were morphed, processed and re-purposed. From finished songs, into song production tools. Traces of the original products, but not direct copies, or at least, disguised.

I dont know much about the law, but I think that the crux of it is the "morph." Was the original product changed enough when morphed so as not to be a direct competitor of the original product.

Clearly the end product of the "tool" does infringe on the original market...to me.

Forever, people in the arts have been stealing ideas from others that lead to output that they never would have had otherwise, and the art is changing them enough or just enough to disguise the theft and avoid breaching copyright laws.

As a practical matter, I don't know how a court will ever quantify a decision.
If someone were to listen to one of my AI songs, how would they ever identify and quantify what was derived from what?

https://soundcloud.com/sunset-poet-of-texas