As far as I understand, "flagging" is intended for things that break the guidelines. AI-generated content is explicitly banned, but only in comments, not submissions.
I think it would be great if AI-generated submissions were outright banned as they fundamentally break the balance of effort that HN was built upon, but as was already stated by another user, YC is heavily invested in AI so there's a conflict of interest there.
Not posting for self promotion is in the guidelines. I have to assume anyone pushing out AI articles is primarily looking for traffic and self promotion, as they didn’t care enough about the topic to write their own opinion.