> I've been contacted a few times by HN moderation and was asked to re-submit some interesting link that didn't get traction on the first try, but it's the first time that I see a link be re-submitted on my behalf. Is that common on HN now?
Not resubmitted but re-upped. That is, we rolled back the clock on it and added some points so that it would get a placement on HN's front page. You can see the stories that get picked this way here: https://news.ycombinator.com/pool, and the system is described at https://news.ycombinator.com/item?id=26998309 and the links back from there.
When a post is older, we email an invite link (as you described) but when it's only a day or two old, we re-up the current submission. That's what happened in the present case. The timestamp munging is an artifact of this re-upping system (https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...).
Thanks for posting great submissions to Hacker News! Btw, if anyone sees a great submission that could use a re-up or a repost, please let us know at hn@ycombinator.com. (It's best when the article isn't your own stuff, but rather something that you just think is interesting.)