He's most likely a costume swap
In Sakurai's "Pic of the Day" post in the Smash Bros. Miiverse section, he recently revealed a brand new addition to the pair of games -- a Male Wii Fit Trainer. In all likelihood the male version is not a new character, but a costume swap for the Female Trainer -- this is especially evident since the pair has the exact same movement in the screenshot.
At least, that's what I hope is the case, as it would be great to have as little clones as possible in the new Smash.
Smash Bros. [Miiverse]