Hackernews clears the existing post check after a given time period. Refreshing old stuff occasionally is not against the rules and sometimes encouraged because not everyone sees it the first time, or sometimes people just like to comment on reruns.
Last one (from GPs list) was from 2017. I wouldn't call this a blatant repost by any means. And there are some good conversations going on too, so there's value in that.
My point: don't sweat it, it was good that you posted this.
Don't worry about it - it wasn't posted too recently so the rules haven't been dented, and it's amusing.