It's not the end of GearScore and the like. The problem is that so many players use it as a staple of who's "good" nowadays that it's bogging down the process. As Cladhaire said, they'll just have to throttle their checks now to reasonable levels. I think everyone will notice a drastic improvement in performance while in Dalaran as well.
GearScore will still be a requirement to play WoW, sorry to say.