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.