Actually I think you got things completely wrong.
Games that they have outsourced to other studios include D2R (Diablo II Resureccted) and they were phenomenally done, true to the original products and almost labors of love.
Games like WC3 reforged they tried to develop internally and completely failed.
Basically outsourcing to other studios that actually CARE about the games they work on is a GOOD thing.
Developing in-house at BLIZZARD is a BAD thing, because they don’t care about the game just your wallet.