You think there would be?

[The idea hadn't really crossed his mind. After all, he'd never heard of other wielders aside from his friends, his Master, Vanitas, Xehanort, and Mickey... well, ignoring everyone from the future.]

I mean, I guess it's possible, but they'd have to be from really far away. That, or from the past. Keybearers just aren't as common these days.