I don't think that is true. The only way you lose it altogether is if you take delivery of the new vehicle and then rollback the purchase for any reason. (Lemon claim, etc.)If the deal is cancelled or changed, I believe / fear it's also gone (from the original car).
If you reject the car and cancel your order the FUSC transfer is cancelled as well. (If you reject and they assign a new VIN the FUSC transfer should be updated with the VIN of the vehicle you take delivery of.)