That Polygon article is hot garbage, refutable by anyone that can do fifth grade math. I know I'm currently just a scrub reading forums and blogging on the internet, but at least I don't post utter garbage like that.
We all know games see their best sales within the first few days or the first week, and AAA titles sell more on hype than any other factor. Staggering the releases only means that the hype has a chance to die before it releases to the widest audience.
SE may come out ahead on this deal, but that would only be if Microsoft throws enough cash at them, because it sure as hell won't be from increased sales.