Making use of AI is the same thing as plagiarism – no difference. As long as you are presenting an idea that's not yours to the public as your own, it's stealing.
Making use of AI can result to plagiarism or not, it depends on how you use it.
Let me explained further, if you use AI on platform like Meta and Google, it will give you links of the source it get the information from. I'd someone use them and not make the reference, that is plagiarism.
If you use those like ChatGPT, they do it in a way that you will not link it to any source which is the difference.
But using AI should be completely forbidden on his forum except to correct someone's grammar.