For what it's worth I have never seen this before and am certainly happy that it got posted again. It's not like your Hacker News experience gets massively influenced by a story being reposted every couple of weeks.
I agree. As someone who visits HN practically every day, I had never seen this before, and the book seems very interesting. The chapters seem hefty enough to warrant a post as they come out. Also, it's not one person that keeps reposting, but different people posting.