The submission I linked is not flagged (at least as far as I can see from my account?). Either there's some non-intuitive stuff going on with the way submissions stay on the front page, or HN soft-nuked it. Either way I think we deserve an explanation and a clear understanding of the underlying rules.
It takes some amount of people flagging it before it shows up as [flagged] but flagging submissions affect rankings before it reaches that point. On top of that "Ask HN" posts also have some modifier on them that makes them drop quicker, these two effects seem to be cumulative, explaining why it dropped so quickly
Does HN always tell you when someone flags it? Or just a critical number of users or something like that?
I see the flagged indicator now and then, but I see it somewhat less frequently than I would THINK things get flagged, admittedly that's all conjecture.
If something is memory holed quickly enough after being flagged, perhaps combined with an automated algorithm that considers certain keywords, then the likelihood of people noticing flagged posts can be kept very low.
Of course this is all speculation, the truth of censorship on various platforms will likely never be known.
