They 99.99999% of the time don't. I think only dang has that ability and he won't really step in unless there are some truly rouge actors.
It's more a question of the article. What we're looking for includes: is the article not too repetitive of recent discussions? does it contain significant new information? is there a reasonable chance that it could support a substantive, thoughtful discussion, or is it too flamebaity/provocative? that kind of thing.
Here's a subthread from yesterday where I went into this in depth: https://news.ycombinator.com/item?id=42911011. Past explanations: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que....
If anyone has a question that isn't answered at those links, I'd be happy to take a crack at it.
(Of course, I could just be misunderstanding how flagging works on the site... maybe the state machine has to transition in order from regular -> [flagged][dead] -> [flagged] after vouching?)