In-game team switching???

@J1ZSOC
Perhaps the key to the mystery here is due to this concurrent "new match timer counting down" that you've mentioned.
It's where-and-when I and others are most likely to leave a Server.
If 5 Players quit a Team and 3 fresh 'Joiners' (of the Game) are newly assigned , the 'balance' might be randomly taken from the other Team .
It could be that all you noticed was the two mates disappearing .

If the rate of fresh 'Joiners' to the Game is considered to be like a steadily-falling light rainfall , then the rate of potential 'Quitters' during any of these 'new match countdowns' could be considered to be like a brief torrential downpour.
Since water itself has the tenacious ability to go almost anywhere it pleases , it's not surprising at all to see that despite the best efforts of Game Makers to 'balance' such chaos , we still see 'wet spots'.