One point I would like to make, correct me if I'm wrong but doesn't the banshee sort of have homing missiles, albeit not as powerful as the hornets. So rather than getting rid of the hornets missiles why not nerf them to a level more similar to the banshees.
Because then banshee vs hornet, would become passengers seats vs boost and dodge, not flying aircraft killer vs aircraft.
I think that's why people have been suggesting removing the homing from the rockets.
I still think that the Falcon would be better than bringing back the Hornet, provided the Falcon is like the ones from the New Alexandria mission, only with a weaker forward mounted turret.
I think that Promethean vehicles aren't likely to happen, for the reason that, as you said, they can teleport, but also because they are the Ur-Didact's personal army. He's dead, so it's likely that the Prometheans aren't going to reappear.However If a new class of promethean arrives, which would rock, maybe a more human promethean, then I see no reason why we could not usher in a new age of promethean vehicles with marvellous speed the like of which we have never ridden before...
Forerunner vehicles on the other hand, are a huge possibility.