I'm sure some active dodging is going on, but I don't think it's as much as you think.
Let's say there are 2 premades on horde and 2 on alliance, combined with also 20 pugs queueing at either side. You would think with 2 pugs and 2 premade teams you would face a premade only 50% of the time as pug. But this isn't the case, and not just because of dodging. When I was ranking we always started without any scouting. Just queue, see what happens.
Now the odds of us, as a premade, running into a pug or premade for our first game is probably close to 50/50 in this given scenario. But since you can wipe the floor with most pugs in 7-10 minutes (depending if the particular faction is nice enough to give the losing team a mark or not), whereas versus the Sarei/Cowlover premade the games would often take 30-40 minutes. Just these numbers alone make it more likely for a different premade to run into pugs a lot more often, because the two main premades are "stuck" playing eachother for a duration that is about 5 or more times that it would take to beat a pug. This alone will make it so that if you queue for an extended period of time you will start to see a shift away from this 50/50, and not in your favour.
The second fact is, at certain hours (early morning, early afternoon, late at night) there aren't enough pugs queueing to start games, and if so - not that many. And the only horde of alliance groups queueing are premades. You can think we, or they, are dodging, whereas in reality it's just all there is.
And the painful reality is, it's very time-consuming already to get to the higher ranks. Especially in a world of account sharing, The Chinese, certain people being able to be online 20hours every day, every week you simply can't afford to just keep playing premade after premade (as a premade), if you do this all day then at the end of the day a guy who is just pugging will get more honor than you - and guess what, he's going to put in 5 more hours than you as well, almost defeating the purpose of premading. Often after 2-3 games vs the main premade a decision is made to wait with queueing, to "un-sync" yourself from meeting them over and over.
Lastly, don't give a premade more credit than that they deserve. Make your own premade, you don't even need Teamspeak or a 7-mages comp to do well. Get some of your friends, guildies or advertise in world. Or queue as a small 5-man premade. Most groups are carried by 1 or 2 players, and also most Horde groups don't even use TS, or spam free action potions. If you put some effort into it you can form a small pug-killer premade in 10 minutes and tryhard your way with potions, engineering and TS to contest any premade.
Also, when you face the same premade twice in a row and get destroyed, delay queueing by 2-3 minutes and queue up again, when you get an instant-pop; leave queue.
[edit] spelling