They're already banned—HN has never allowed bots or generated comments. If we have to, we'll add that explicitly to https://news.ycombinator.com/newsguidelines.html , but I'd say it already follows from the rules that are in there. We don't want canned responses from humans either! Edit: It's a bit hard to point to past explanations since the word "bots" appears in many contexts, but I did find these: https://news.yc…
Not that I want AI responses, but that's my 2 cents.
I also think there's a difference between a "bot" account, which I think the common definition of would be one that only or mostly posts AI responses, and posting a comment on your account that you don't claim is from an AI (or even when you do as an afterthought).
While many people wouldn't defend the first, more might defend the latter as acceptable, and I wouldn't say a "no bots" policy would be interpreted as banning the latter.