I'm gonna invoke Poe's Law on this one. That being said, it's pretty common knowledge that first-wave beta access generally goes to streamers, big-name fansites like MMO-Champ and WoWhead, and other people who can get word of mouth out, and randoms are selected to fill in the gaps, with more randoms picked as time goes by to fill the beta in and get a wider array of playstyles and skill levels (you never know what sort of insanity a player who isn't focused on min-maxing the level grind can come up with) so feedback is as complete as possible.
Of course, what they do with that feedback is a valid argument to have elsewhere.