I think it's reasonable to assume that this whole thing has been a marketing campaign to get people to finally have a reason to switch to IPv6.
All kidding aside, IPv6 isn't even required for their website or this traceroute trick. He just set up an in-addr.arpa reverse DNS zone to reverse resolve particular IP addresses to specific values. If you had a block of 20 IPv4 addresses, I don't see anything stopping you from doing the exact same thing.