No, it would seem to be a good idea, from Dish's point of view. What would be a bad idea would be for Dish to do all of the work to win back a customer who had just cancelled, only to end up with that customer still being ticked off at Dish because now they can't watch their archived recordings from the external hard drive.
Incentive not to cancel in the first place. Don't let them think there's no cost to dropping and returning.