[folmar]

> If I type a series of bullet points into ChatGPT and ask it to re-phrase them in better English prose, am I plagiarizing?

I think the OP's point is that you could be, and should check, as such models sometimes reproduce parts their training set. You should check what you send, or, in other words, take responsibility for the tools you use -- the tools that are bread and butter are somewhat excused, but LLM are not at the moment.