This is what I have been trying to say as well.....Now I might be wrong, but I have a feeling that somewhere it was said that the apprentices lost their hearts at the same time. :v And seeing how Xemnas is the one that kicks AtW out of Radiant Garden not too long before Maleficent takes over, that would mean that between BBS and Maleficent taking over, they would have lost their hearts.
And since we're told BBS takes place ten years before KH1 and Maleficent took over nine years before KH1, they might not have even a year to have become Nobodies. If that's the case, then I don't see how Ienzo would have had enough time to grow up. Quite simply, there's not enough time.
So unless BBS takes place sooner than what we were told (like Smile theorized about), I don't see it.