I will disagree with that characterisation. IMHO: In some cases no, it's not different, there are clear lines from inputs to output. In some cases yes, it's different from any one input work, it's distributed micro-plagiarism of a huge number of sources. In no case is it original.

But I think that this is legally undecided and won't be decided by you or me, and it is going to be a more interesting and relevant question than "is the LLM model is very like the original work", which it clearly isn't. That's like asking "is this typewriter like this novel?" It can't be, but the words that came out of it could be.