This is part of an experiment in giving good HN submissions multiple chances at the front page. If you have any questions, let us know. And if you don't want these emails, sorry! Tell us and we won't do it again.
I've had several submissions put in the second chance queue. Some take off, some don't. There are a few I plan to keep putting in rotation myself every few months, at least for a while. (Not on any particular schedule, but as I'm reminded of them, often from other relevant discussion.)
It often takes a few repeats for an item to get traction. There are also numerous perennial favourites which show up every few years.
HN itself has existed since 2007. Memories fade, and new souls appear. xkcd's Ten Thousand applies.