HN already has a mechanism for flagging posts. If flagging low effort/trivial show HN posts were normalized, I suspect it would work just fine: if a human can't easily decide whether or not to flag it, they likely wouldn't.

As dang posted above, I think it's better to frame the problem as "influx of low quality posts" rather than framing policies having to do explicitly with AI. I'm not sure I even know what "AI" is anymore.