After waiting for a while (long past the estimated wait time), and clicking on the “Cancel” button, the game does not make you leave the queue, but instead makes you enter the game right away.
This bug still exists even with the latest patch. This is so annoying that I have to play a game even if I have something coming up and have to go away from computer. And if I have to forcefully close the program, or stay AFK in the game, I get reported or moved to the leaver’s queue. So unfair.