First about grandfathering - once you no longer received distants from Dish (for whatever reason - your choice or their court order) you are no longer grandfathered - it cannot be transfered. You must live in a white area for each network - or get a waiver - or use the RV exemption to get distants with another provider.
I have a theory why Dish is not allowing most of those who get or can get locals to get distants thru NPS.
One interpretation of the law can be: You may not receive distants if your distants provider is able to give you locals.
But another interpretation can be: You may not receive distants if your provider is able to give you locals.
Even though Dish is separate from NPS, they may be taking the broadest possible interpretation, by saying they cannot allow distants on their box, as your provider, if you are receiving locals, even if an outside source is providing the distants.
I think if that is the case, it will help them in court to allow what they are doing. I have to believe they talked about that and decided it was more risky to allow distants with locals, than to just allow distants if no locals were available.
I do not see that as working "in concert", but rather making a decision what they will allow on their equipment. In fact NPS could well say they want to give more people distants, and Dish won't let them. Again, that would certainly not be working in "concert."