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.