I doubt it. Look at what Directv ended up doing several years ago when they got the 3 transponders at the 110 orbital location from I believe was USSB.
They could have easily let the licenses expire, or worked out some sort of transponder swap with Dish, instead they went ahead and launched something to keep the licenses active and to not loose them to DISH Network.
Same thing will happen here, I wouldn't be surprised if they launched their new 3D HDTV service from this slot, or put something insigniciant up there just to keep the licenses active and not allow them to go to Dish.
16 Transponders could easily launch HD Locals in an additional 30 Cities, something which Directv does not want to see happen
DirecTV is paying significant lease fees for each TP so there is so incentive for them to release the TPs they aren't using. If Dish does get access to some additional TPs, I would think Dish would use these for CONUS programming.