The only requirement to submit something to HN is "it's interesting". Random evergreen content with no contemporary relevance gets submitted all the time, hence the (YEAR) rule. My 8 year old GitHub repo which hasn't ever been significantly updated gets submitted to HN atleast once a year:
https://hn.algolia.com/?q=https%3A%2F%2Fgithub.com%2Fminimax...If other users didn't think this submission about HN rules was interesting, it wouldn't be upvoted.