At the end of the day, it all is written in our agreements. I'm not too lazy to look at mine, but just don't really care considering I have no intention of moving. If the agreement states canceling is at a cost, nothing else, too bad so sad. If it states a clause of moving to a location proven to have no LOS, then they're wrong. If there is a clause that states subject to change, then once again too bad so sad. It's cut and dry no matter what. If nothing is in the agreement, I'd say Dish is liable to do what they want.
Again, I side with the customers. Ethically, Dish needs to be able to provide their service prior to charging an ETF. But we're in America. Ethics and legality don't go hand and hand.