In this case I e-mailed hn@ycombinator.com to inquire about why it was flagged, and Dang jumped in and lifted the flags after quickly scanning things over to check that it was legitimate.

Basically, users flagged it. I think the explanation Dang gave me in his e-mail reply is almost certainly correct, and it doesn't contain anything sensitive so I'll just share it here:

> All I can tell you, though, is that users flagged it. We don't know why they flag things, and can only guess. My guess in this case is that it's a combination of some users having covid-story-fatigue, and other users disagreeing with the view in the article. As you know, this question has become politicized and is getting more polarizing as we go forward.