Open source also requires attribution for derivative works [1], not just verbatim copies.

[1] https://en.wikipedia.org/w/index.php?title=Derivative_work&o...

Thanks for that link to the definition and requirements for something to be considered a derivative work.

I think my interpretation, based on your link, holds: unless the LLM output (transformation) substantially bears the original source code author's creation and personality, there is nothing to give attribution to.