Not picking on JD here, just happens to be the dealer I'm talking about.
When I was shopping I sat down with the local JD salesman and wrote up a build sheet for a new tractor, determined a price, couldn't find one on a lot so determined, if purchased it would be ordered from the factory, 3-6 week delivery time, factory would notify when build date was determined. I think the same situation that the OP of this thread was in.
As it turned out I did not order the tractor. But if I had and my salesman/dealer later found an older model on another lot somewhere and could trade for it, they would have contacted me with the new "deal" and we would have renegotiated the price. I am very confident of that. I believe in my local salesman/dealer.
If I had went down this road and my local salesman/dealer had pulled this switch, they would get their tractor back and I would contact the area JD representative and expose this deception. It was absolutely intentional with the intent of selling the OP a carry-over model at current model price.
As for a list of questions that must be asked and answered and written down, that's pretty much what the OP had when he signed the contract to buy a new built tractor. Isn't worth much when the dealer doesn't honor his part.
When I bought my Kubota the dealer was supposed to move it from it's current location to one of their dealerships 100 miles closer to my house for pickup. We set a date for that transfer and pickup. They were busy and could not make the move date. They called me and let me know the tractor would not move until the next week. I said that was a problem for me. They said, we'll take $500 off the price if you can pick it up at it's current location. So I drove the additional 200 miles and saved $500. I was happy, the dealer was happy. That is how changes are handled in the honest business world.