In 2v2, if one player concedes, does their team lose, or does only that player lose?

Ruling: There is currently no rule that dictates a player conceding equates to their team conceding. Only the conceding player loses and removes their cards from the game.

Nuances:

• This allows strategies where one teammate can concede to remove their battlefield effects (like Aspirants of the Arena) to help the team win
• This is very likely an oversight and expected to change in future rules updates