Mechanical transformation is always considered derived.
The difference is that if humans do it, there's plausible deniability that it is derived.
I mean, even when humans do it, we still do clean room engineering.
It goes further though: LLMs are just a tool, and tools don't get rights, humans do.
Humans having the right to learn from a few dozen books and projects is not the same as a tool that infers output using all copyrighted works know to man.
It could be the same act - but not necessarily legally the same because of the actor.