(If anyone has stats for how the Elo changes on Voobly and HD, that would be good to check.)
I don't really know the Voobly formula, but it was applied like a team is just a player and the you can use the 1v1 formules to calculate the gain and losses of a team. Then afterwards that number is shared between all players.
So in the case of 1600 TG AVG Vs 1600 TG AVG, a win will result in 16 point. These 16 are somehow shared with the team. If it was a 4v4, then everyone gets about 4 points. If it was a 2v2, then it is 8 points. Not sure how this division was exactly calculated.