C. J. Prahalad of the University of Michigan is an expert of this phenomenom, and he dubbed it, "The Rule of 3". I have studied this in several industries, including auto and telecommunications industries. I had not followed the entertainment/cable industry at all, so your data filled in a lot of holes.
Personally, I do not see the business model change until such time that the consumers stop paying the current prices. Unfortunately for me, it seems the entertainment generation is a multi-generation thing. That is, I doubt too many people will stop buying or call their cable operators for discounts.
I doubt entertainment will get down to three, but the basic reasons for all the mergers are the same. Definitely nothing about the cable bill will change until viewers convince Disney they’re so annoyed at paying 18 cents for ESPN Classic they’re actually willing to stop paying 4 bucks for ESPN.