DC - do you remember/recall if they said HOW MANY Dumbos would be on each spindle?
The current one holds what, 16? So if it's merely doubled, then we could assume that they are using the existing Dumbo. If it's more than 16 per spindle, well, they must be making new ones...
I don't think it's ever been said officially. The only thing we would have to go on would be the concept art.
Even still, a general "spinny uppy downy ride[y]" ride system is pretty much almost an amusement park commodity. In the MK you already have 3 of them between Aladdin, Dumbo, and the AstroJets. You've got a couple of them over at the Universal parks too.... and I'm pretty sure most of us have seen similar ride systems in our local amusement parks as well.
Since the ride system itself is pretty much available off the shelf, I would think Disney's decision would have to include the simple question of is the cost of a new one really THAT much more than the cost to move the existing system? and would the more intangible cost of being able to quickly turn around (close one, open the next) be worth what may end up being a negligible hard cost difference?
Now if you notice, I'm specifically mentioning the ride system itself. The decoration and dumbo vehicles themselves which are custom to the Disney Park themselves could very well be recycled and transplanted from one ride system to another, And ultimately it would be a much cheaper and quicker prospect of just removing the Dumbo's from the Existing Ride System arms and carrying them over to the new location and attaching them on the arms of the new system.
Turn around time, I could even see Disney with it's history of pulling off incredible feats managing to close down Dumbo one evening, removing the Dumbo elephants, attaching them to a new ride system, And have the new location actually open the next day. (Off-season hours of course).