My understanding is that HN is monetized e.g. marketing is explicitly permitted by founders etc.

I guess that's not conventional monetisation.

They arguably do. Just look at the valuation of YC. They are just being smart about it.

They do not monetize but may do probably something worse, infotize or narratize (just invented words). By using an almost neutral, altruistic platform to subtly control/constrain the narratives on certain tech overlords. As much as I love HN, I do not agree with their reasoning to flag some of the posts that are negative to the tech elites.