Double eliminations in 2vs2 tourney would result in the same ammount of games like in the last 1vs1 tourney - 15.
Actually it's 7.
15 games passed by pretty quick in the 1v1 tourney. So this one could work out too.
Ofcourse according to the rules, 80% of players must agree first in order to change the rules. If we analyse extraordinary situation, at least 2-3 members must make a walkover (refuse single eliminations) so the only way to keep the tourney alive will be making double eliminations. So all in all the first variable counts the most: 80% of players must agree first in order to change the rule.