I agree. I "revived" the comment by clicking on the timestamp ("33 minutes ago") and then clicking "vouch". I believe only users with a score of 200+ (points? karma?) can do so.

Been here 8 years, always wondered how comments died. I assumed it was algorithmic. TIL

“[dead]” usually means algorithmic (could be as simple as an account registered via Tor that hasn’t been vouched for enough times). “[flagged][dead]” usually means it was flag-killed by users, except I’ve been noticing some AI written comments that are flagged instead of just dead, but they’re minutes old so unlikely to be user flagged.

There's been an "AI comment detect" algo trialed and running for a month or so now.

If you see any probably human comments tagged as Mr Roboto either vouch (weak indication, needs a few others to boost) or email hn@<this site> for dang / tom to cast a meat based eyeball over it.