I don't think it's a grift in the negative sense but this is absolutely a marketing comment. They're doing exactly what they say to do in the comment. They're on HN where at least some of their target market is. They have a product that is relevant (right down to the headline/CTA). They didn't just post the link but put it at the end of an informational comment.
10/10 meta-promotion IMO
Debatable I suppose but I don't feel I do. That's what likely means - I feel I have enough suspicion, the coincidence is too strong, the stars too much in alignment...
Hard to recreate but at the time I commented it was also the top comment with only a few others and it was on the front page. I've been a HN'er for a while and this is a rare situation to say the least if it's not a setup. I'm not willing to die on the hill and would gladly admit I'm wrong, I just see it as very suspicious forum spam as the most likely scenario
They also likely were involved in the the original question getting posted so they could provide that answer which is what makes it an entirely fabricated grift