If the question is "Will there be a 2v2 team mode implemented in Dominion Online?" then I don't think there's any evidence that it will happen. At the very least, I wouldn't expect to see it happen this year. There are no official 2v2 rules for Dominion, so unless they appear in Empires, they would have to be invented and implemented. We already know that Making Fun have their hands full implementing Adventures, and it's unlikely that they'd try to add an untested game mode in less than a year before they lose the rights to the game entirely (although we've been surprised by their decisions before, so who knows?).
How would you expect 2v2 to work in Dominion? Just play a 4p game but add pairs of scores together? Would Attacks affect your partner? Would cards that say "every [other] player"? I'm not saying there's anything *wrong* with it, just that without there being official rules for it I don't expect to see it in any official implementation while there's still so many other priorities to deal with.