i agree that it just doesn't seem like something they would do, making them the parents. but whoever was it that said it...the misleading factor...i think that's an important consideration when it comes to any of these speculations. i mean, all of the theories and stuff leading up to CoM and KH2 had people being mislead in all directions, like when they thought that DiZ had to be the leader of the Org because a trailer showed him talking to Riku with a hood on. i have no guess for who it is really, but the theory that feels the most right to me is the one about them being Keyblade masters of some legendary status, possibly each one representing a different one of the four paths.
i always assumed that he was talking about the Keyblade choosing Sora (thus finding out why he himself had the Keyblade, a question he left the Organization for) and that it was more of a translation problem. doesn't he say "he" in the English one? *can't remember*