As a moderator, I've been trying to use a light hand here, but I do think I need to step in, because the conversation has clearly gone sideways a bit.
The Core Team is still working on an official LLM policy, but I expect that it will allow people to use LLMs to help with contributions (which includes posts here) as long as they take personal responsibility for the result. I don't think there's an inherent problem with LLM assistance in writing forum posts, but I do think there are inherent risks that people doing it need to be thinking about as part of their personal responsibility.
The first risk is that the LLM will launder misinformation. It is always tempting as a writer to say something that sounds convincing but which you can't actually back up, just to try to win an argument. As humans, we usually see that as a form of lying, and that alone stops most people from taking it too far; and when we do do it, it's often discovered, with real costs for our personal reputation and pride, and the fear of that also holds people back. But LLMs do not have any sort of semantic model of truth or evidence, nor do they have moral leanings or concern for their reputations; it is well-known that LLMs will often confidently state things that have no foundation at all. And when an LLM says something that sounds convincing, it is much easier psychologically to leave that in unquestioned than it would be to write it oneself.
The second risk is that the LLM can generate text much faster than a human can. Even human conversation can sometimes fall victim to imbalances. Most of us have probably had professors who rambled their way through their long-familiar lectures while their students struggled to really process anything they were saying. (I have a distressing tendency to do this even in personal conversations.) Still, the fact that it's a human who's writing or speaking forces a certain level of proportionality. In fact, if I'm really thinking about my words carefully, it often takes me much longer to say something it than it does for someone to understand me. LLMs do not have this constraint; an LLM is a program that generates text, and it will keep generating text as long as you ask it for more, and by the magic of massive parallelism it can do that really fast. The result is that it's quite easy for an LLM to dominate a conversation, at first by generating so much text that everyone else is spending all their time just trying to keep up rather than responding, and then by attrition, as people stop trying to keep up because they no longer see any value in participating. This is not respectful of other people's time.
So I think it's incumbent on people who use LLMs for posting to always be carefully and rigorously reviewing everything the LLM writes, both for accuracy (paying special attention to claims that you might not fully understand) and for conciseness and non-redundancy (trying not to over-burden everyone trying to engage with the thread). The result will probably be that the LLM will never actually save you time; a theoretical you who was just as capable of writing that post could probably have written it faster. The value of the LLM is that it might help you write posts you couldn't have written before: you will learn something new with the help of the LLM, which now you can bring to bear in the conversation.