Yep. Most (all?) of Dish's customer service is done off shore in places like Philippines and India.
Most of DirecTV's customer service call centers are done in the United States in "cheaper" locals like Idaho and Oklahoma. They do have 1 call center in the Philippines for overnight support.
Not sure of the numbers or the percentages are, but Dish definitely has both On and Offshore support. Infact, it is usually suggested to call during the day to get a onshore CSR. I personally I have not seen any numbers that would suggest using "Most" to describe their support structure and it definitely is not all.