Uh, not really, no. Otherwise I suppose Riku and Sora both would've been Duel Wielding more than just the times we saw them manage that at, Mickey would've Duel Wielded too, and MX would've pulled another Keyblade or something in the secret endings. And if not him, then DS.
And let's never forget the fact that when Roxas and Sora Duel Wielded for the first times in KH2, the fact they had two Keyblades was kind of a big deal.
Maybe dual wielding is an extrem form of wielding that you can't handle until a certain point in your life.