My slightly informed idea as to what really happened:
EA and Ubisoft struck a deal with MS several years ago after seeing the total outrage that their DRM heavy software created. They likely approached Sony and Nintendo as well. When Nintendo told them to screw off, EA decided to try and bigdog them by announcing that they will not be creating software for the WiiU...to which the entire WiiU fanbase simply shrugged their shoulders and played a Mario game. Sony likey said, "we'll see" knowing that MS had already struck a deal with them. They simply waited until MS announced their new hardware and the policies to go along with it. After seeing the crazy amount of backlash, they told EA and Ubisoft to essentially f-off. All of the negative press surrounding the XBone gave them enough leverage (along with the fact that they are a much more mature console maker who understands their demographic) to do so. At this point, MS likely decided to break contracts with EA and Ubisoft concerning DRM and informs them that the DRM business is their problem. I'm sure there were financial ramifications to this, but after seeing Sony totally dominate them in console pre-orders, they likely had very little choice.
I have absolutely zero doubt that MS is ONLY doing this because they saw their projected sales figures drop. I love the 360, but I have never trusted them. They are ONLY in the console market to turn a profit and have very little insight into their demographic. I'm going back to Sony for the PS4 (PS2 was my console of choice in the prior round). It's not so much the fact that they want to make tons of money, so would I. It's about where I think MS is trying to go, where they want to be, and how very little they truly care about the industry, the gamer in general, or the individuals that pay for their products.
It's not like it matters which system you buy anyway. Unless you really need to play the new Halo game, I think you'll find that almost all of the big titles are going to be cross platform (to an even greater extent than is currently seen). There is very little difference in the two systems' hardware and architecture. This was done for a reason.
Despite this attempt at redemption, MS has already lost the race in this upcoming generation.