Microsoft has been down this path before the Nvidia and the original Xbox. That debacle made it so that Microsoft never had a chance to sell the Xbox at a profit, because the deal with Nvidia said that the cost of the graphics chip would never change over the lifetime of the Xbox.
I think Microsoft is just trying to protect itself from the same thing happening again.
Author of science fiction and other genres, I write under the pen name Desmond Shepherd. The second season of my series The Permanent Man premieres on November 11, 2014. Pre-order the season premiere The Walls Have Ears on Amazon today!