Here's an example of Microsoft attempting to shove platform exclusivity into a deal (thankfully, they backed off): http://www.eurogamer.net/articles/2013-12-04-microsoft-revea...

This sort of thing is not specific to Microsoft's gaming business. Microsoft's habit of using Windows OEM licensing as a tool to prevent computer manufacturers from shipping other operating systems (especially in the 1990s) is well-documented, for instance.

In your example, the Visual Studio licenses are in-house to the development company. There is a different set of license agreements in place regarding the technology shipped out on game discs. Microsoft is well aware there's more money to be made there than from VS licenses, so they're more flexible on toolchain/development contracts than they are on middleware and production library contracts.

Ummmm, the article you've quoted is related to publishing contract and not a licensing agreement. Exclusivity on publishing is very common. You said that it's also "almost always" a part of licensing. Licensing is what I am curious about since I've never heard of anything like this.

I also believe MS had been sued for the OEM racket in 90s and lost so, while it might be true, it's almost 20 years later now and also, I am not sure it's a licensing contract. Looks more like a re-seller/dealer relationship.