Users flagged it. (Mods didn't touch it or even see it.) We can only guess why users flag things, but in this case I don't think the article is a basis for a substantive, thoughtful conversation so I think they were probably correct to flag it. It's too sensational/inflammatory a story, and there isn't significant information there.

The downside, as you say, is that flagging it will appear to confirm some people's suspicions about suppression, censorship, etc. - but that happens all the time on all such topics, and I've learned there's not much we can do about it. Patiently presenting the facts doesn't help with inflammation of sinisterness. (Fortunately, it does help with the majority of the audience.)

The details in the article may be factual, but that's not a sufficient condition for a good HN thread. There needs to be something of intellectual interest, and 'celebrity attends private meeting with other elite celebrities' is not enough information to count. You can see from the comments that people are mostly flaming for-or-against, and/or just making things up. The meeting being secret makes a vacuum that people fill up with their imaginations. That's natural and human but it's not good for thoughtful HN threads.

Also, it looks like the title was editorialized, which is against HN's rules (https://news.ycombinator.com/newsguidelines.html).

p.s. Btw I may be mistaken but I vaguely recall that Sam has attended that meeting before- if so, then his name is higher up in the article purely because AI is newsy these days. Otherwise they'd put someone else's name there - that's how the eyeballs get glued.