They will try to put "safeguards" in place to prevent this, but the query need not be in such straightforward terms. It 𝒘𝒊𝒍𝒍 take place, and almost certainly already has.
I hadn’t thought of this until now although I suppose it is obvious: LLMs will make plagiarism much easier (“Gemini, rewrite this in my voice such that it won’t be caught by anti-plagiarism software “).