If the outputs of the model are found to be not covered by copyright in the first place due to established legal doctrine [0] then developers will not be liable for copyright infringement.
So the only reason for providing attribution will be as a product feature that some developers might want to use.
I personally don’t list every artist that has used a I-IV-V progression in one of their songs and generally lump it into the recognition that my artistic foundation relies on preexisting culture. But hey, you do you.
[0] https://en.wikipedia.org/wiki/Abstraction-Filtration-Compari...