Is there? I enable showdead and don't see it. There are the occasional spam and vulgar comments, but not that much.
Any "AI slop" being posted seems to come from actual HN'ers who think they're being helpful, and is often downvoted. But there's not much.
So I'm not sure this is a problem that currently needs any new solutions? I don't see AI bots taking over the discourse at all. Not even a little.