It would be easier since they have a model to base it off of, but it still would be largely time consuming to recreate them all over again.
Random question: Do you guys think we'll have more varied landscapes, instead of it depending on seasons like Unova? Outside of maybe Twist Mountain, Unova wasn't really that varied of a reason when it came to landscape. Sinnoh had all of the northern routes covered in snow, as well with some more varied landscapes in general. I'd just love to see some more variance with this game, especially with the 3D.