Edit 2: I've replaced the question mark with quotation marks following a suggestion by bee_rider: https://news.ycombinator.com/item?id=34713987.
-- original comment: --
We sometimes add a question mark when a title makes a dramatic and divisive claim, because otherwise readers who read the title might think that HN (or its admins) are somehow endorsing the claim. We don't know what the truth is and are neither agreeing nor disagreeing with the claim.
Edit: I dug up a few other examples where we've done this:
This is the year of the RSS reader? - https://news.ycombinator.com/item?id=34105572
Anthropology in Ruins? - https://news.ycombinator.com/item?id=34049130
The great Covid and smoking cover-up? - https://news.ycombinator.com/item?id=33869176
The basic idea is that adding a question is a flame retardant because it tends to dampen the meta-comments about the story, e.g. complaints that the admins are taking a side or whatnot.
In this case it's not really working, because the question mark is also generating lots of meta-comments. But maybe fewer than we'd get without it.
Meta comment of my own: it's not only impossible to please everyone with moderation calls like this—it's seemingly impossible to please anyone. That's why it's really helpful to have a first principle to rely on—i.e. to know what you're optimizing for. It occasionally makes it possible to answer an otherwise hard question rather easily.
https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...
You are endorsing the claim when you override the ranking system and allow opposing views to be flagged and thus never appear for balance.
Re flagging: that's supposed to be for comments that break the site guidelines. If you (or anyone) see a comment that breaks the site guidelines and isn't flagged, or a comment that is flagged and doesn't break the site guidelines, remember that we don't come close to seeing everything, and that you can always let us know at hn@ycombinator.com. It's best to only do that in egregious cases though. For non-egregious cases, it's best to remember that consistency in moderation is impossible and not sweat the small stuff.
Your stance seems to be that this unsourced conspiracy theory is a story worth discussing because, and only because, it is Seymor Hersh making the claim. Then make that clear in the title: "Seymor Hersh claims America took down Nord Stream", or something. It goes against the standard HN practice of stripping out any such attribution from the title, but it's also not standard practice for an article to only be worthy because of who wrote it.
Edit: I've put quotation marks up there now, as explained in the GP.