Something to know about the major publishing houses taking in the "smaller" studios is that often times this is just a convienance factor for both parties.
EA bought studios left and right to bring them inhouse and cut out middle men. Yes they often flexed their muscle and made bad decisions but they have learned from their ways. Blizzard is very much doing their own thing and reaping the lack of middleman being needed. When your bosses dont have to get the legal department involved to start negotiating contracts to ship a game, its all the better.