At first, I thought this theory of "SS" being a bird was just some more, uh, baseless speculation. But you know, you (or whoever it was that made the vid, I assume it's the OP though) actually make a pretty darn good point.
The only problem I see with the theory, though, is that Aonuma said that "Link won't be flying like Pit from Kid Icarus" or something to that effect. This means that that particular part of the theory, the wings sprouting allowing Link to fly to safety, is probably debunked already, but that's just a minor detail since it's possible that "SS" MIGHT fully transform into a bird and carries Link down there or something.
In fact, now that I think about it, I think that this may possibly be true. Although, as you said, we can't be sure until they leak some more info or the game comes out.