What happened to Korea's "gup"s on that page?
They were replaced by K's (because gup is simply Korean for kyu), and the current list reflects the Hankuk Kiwon system as explained at http://senseis.xmp.net/?Gup#toc2
Even if there is a new dan-kyu rating system in Korea, the gup rating is still relevant. Multiple times I have met Korean Go players and described myself as a 1- or 2-dan, only to receive a gasp of astonishment at the mistaken surprise of meeting a professional-strength go player. (Then I have to correct the mistake, a downer for both parties.) :)
Basically, the gup levels make communication with older players easier, even if no one is handing out new gup ratings (this could be debated). Deleting them, rather than adding a caveat or placing them elsewhere, was a mistake because it takes away information that is still meaningful.