IMHO it's very misleading to claim that some LLM wrote all the code, if it's just a compression of thousands of peoples' codes that lead to this very LLM even having something to output.
In pragmatic terms though, innovation like that doesn't happen often. LLMs could do the things that most developers do.
That said, I don't agree with the notion that LLMs are simply generating content based on their training data. That ignores all the work of the AI devs who build systems to take the training data and make something that creates new (but not innovative) things from it.
No. He merely reimplemented it.