Just a guess:
Maybe the person who saw it as [delayed] is using a third party HN reader app and the HN website itself filters out delayed comments while returning it via the API as the [delayed] string and expecting clients to do the filtering?
Maybe the person who saw it as [delayed] is using a third party HN reader app and the HN website itself filters out delayed comments while returning it via the API as the [delayed] string and expecting clients to do the filtering?
I’ve also never seen it in the many users of (mostly many times daily) visiting HN.