Interesting. It only strikes me as odd that neither blog linked on that site mentions it, and the IP address won´t resolve on any DNS server around. What gives?
$ dig news.ycombinator.com 1.1.1.1 +short
news.ycombinator.com.cdn.cloudflare.net.
104.20.43.44
104.20.44.44
Edit: It occurs to me you mean reverse resolution. A dig +trace seems to stop at ns3|7.cloudfare.com.