Anybody can flag a post or a comment on Nextdoor, and people do so quite a lot. Most of it is "this guy said something I don't like", but depending on the person reporting, they might be savvy enough to look up a rule that's actually violated by the post/comment they didn't like. Leads of neighborhoods where the post/comment showed up then get a notification to vote on whether to delete it or to keep it.
Ah, but for these threads you get the "this post has been deleted" for many posts which 100% are still there. It just takes extra work to be able to see them.
Once you have seen it and dug into it a bit, it feels very intentional and sneaky.