2 man competition is really low, so there's never really a "meta". Really far into the season you even sometimes see two DPS combining their forces and playing together - if you can solo a high GR, you can also do a 2 man high GR on a similar level, especially if one forces on trash and the other one single target (and the trash killer can drop Stricken for Esoteric or so).
In several seasons everyone quit and we were only 2 people left so we just played the two classes that we enjoyed most. I think we've probably tried about every class as zDPS (maybe except for necro and DH because didn't like them) and every class as DPS... and just continued to push with what we enjoyed the most. Then you filter diablorank.com 2p rankings and see if you're #1 "without class X" or whatever the meta is. At the end of the day, rankings are about paragon anyways, and that's impossible to combat since Blizzard hasn't banned botters recently and paragon is absolutely skyrocket in S12 with the power creep - so instead of focusing on "what's best" and "how to get rank #1" I'd strongly recommend to play whatever you enjoy most and set your own goals and satisfy yourself with "well, we were #1 legit players of this combination" rather than "yay, we made rank #253 with the cookie cutter combo".