> [US jurisdiction]: Anything in the result written by the LLM can not be copyright by anyone.

This is a bit stronger than the actual report where this has been discussed finds. See part 2 in https://www.copyright.gov/ai/ for details, but TL;DR, parts where humans have control over the expression may be copyrightable. But working out which parts those are is likely a difficult question (would likely require proof of provenance across many of those LLM sessions)