Arc System Works has done right by the Switch with BlazBlue: Cross Tag Battle, which is set for a simultaneous release with PC and PS4 in June -- not having to wait months for your platform of choice while the community figures out the game all the while is a huge plus in the realm of fighters. The Guilty Gear XX Accent Core Plus R Switch port is also a good show of faith in the system, but it's still nearly a six year old game.
So far we don't have real announcements for Guilty Gear Xrd: Rev 2 or Dragon Ball FighterZ, though a recent tease may hint at a plan going forward. Arc has just tweeted out that they're going to bring more games to Switch in the future beyond what they've already committed.
It could be anything, but with the wild success of FighterZ it's probably the first thing they're rushing out of the gate.