Sure, we sometimes turn off user flags when the article contains significant new information and the topic seems intellectually interesting.
Most of what we do is "done silently and only admitted to after the fact". HN is a curated/moderated site; it always has been. We don't publish a moderation log but it's always possible to get an answer to a question—you just have to ask.
>>dang+(OP)
I welcome the curation and moderating of this site! I'm more imagining that those stories got posted to https://news.ycombinator.com/favorites?id=dang, with some time delay, so years from now, amateur historians can see what articles were deemed noteworthy in such a fashion.