...They would involve a scene cut from the vanilla game, in the trailer for the DLC?
I think what he means is:
In the main quest, theres one part you jump on the dragon and fly on him, but the second he hits the air, it goes to a load screen and you dont actually get to fly the dragon.
I think what he was saying is that the dragon flying they showed in the DLC could be nothing more then a loading screen transition from one place to another.
I personally think its a little more then that, because if that were the case i dont think they would show dragon flying the the trailer if it were just another load screen transition.