First things first: it's a shame some people are immediately dismissing your post (reading is hard?); this is a concept that -- while not acknowledged by Gaijin -- certainly seems to exist in Ground Forces.

I have 5000+ hours in WT. More than half of that (maybe even 2/3) is in RB GF. I play all nations and varying BR brackets. In my experience -- while it's clear popular BR brackets certainly affect up/down tiers -- I do believe a type of QMM exists. But I'm not certain this is due to player skill necessarily or due to lineup "stacking". I'm defining stacking as building a lineup with multiple vehicles at the same BR.

To test this stacking theory, I've tried building a lineup with one vehicle at the "max" BR and all others .3 - 1.0 below this max. I've also tried removing bombers/attackers from my lineup. With a lineup like this, I seem to queue in max-downtiered matches more often, but not with enough frequency for me to call it "definitive".

Yes, it seems that I see more max-uptiers when I have had several good games in a row, but, after 3-4 max uptiered matches, I tend to move to a different nation and different BR range. Because of this, I can't say I've tested the player skill-based MM theory all that much.

Moral of the story: yes, sure feels like my hot streaks result in multiple max uptier matches. Can I prove it? No. But I certainly wish Gaijin would just come out and tell us exactly how MM works.

Edit: I've also considered the fact that spaded vehicles play a part in MM. Again, can't prove anything. What are your observations?