The actual design has Kirby turn pale white like Wii Fit Trainer, as well as giving him the female hair. I'm surprised, because the Male Wii Fit Trainer exists. I thought he'd at LEAST get a blue headband.
I dunno, I just kinda doubt that Kirby would get a ponytail from the Male WFT, even if he his an alternate costume. Wario was at least the same character with different clothing, but the WFT's alt costume is a different sex entirely (assuming it IS an alt costume).