But this time it seems Microsoft didn't just omit certain key, unflattering facts - a move we expect from IT vendors when presenting their version of the news. It went a step further, by positioning the GPLing of the code as something it clearly was not.
Microsoft called it a "break from the ordinary", a "significant milestone," and a "prime example" of customer demand being a "powerful catalyst" for change. In realty, it looks like Microsoft messed up and was doing the right thing - if only to avert an embarrassing legal problem.
We don't know why Microsoft positioned the news as something it was not. Maybe it was because of the strategic and political importance of Hyper-V to the company, the unmissable kudos of embracing GPL and helping Linux on Windows, and how such an act could finally silence doubters.