Playing the devil's advocate:
Shareholders want reasoning behind such large changes. It's really nothing more than describing where MSoft has been and what its strengths are
We will do this by leveraging our strengths. We have powered devices for many years through Windows PCs and Xbox. We have delivered high-value experiences through Office and other apps. And, we have enabled enterprise value through products like Windows Server and Exchange. The form of delivery shifts to a broader set of devices and services versus packaged software. The frontier of high-value scenarios we enable will march outward, but we have strengths and proven capabilities on which we will draw.
and what it recognizes as it's weaknesses
It is also clear to me and our leadership that we must do an extraordinary job to succeed in this modern world. We have delivered many great products and had much success in market, but we all want more. That means better execution from product conceptualization and innovation right through to marketing and sales. It also means operational excellence in cloud services, datacenter operations, and manufacturing and supply chain that are essential in a devices and services world. To advance our strategy and execute more quickly, more efficiently, and with greater excellence we need to transform how we organize, how we plan and how we work.
It then proposes the solution: the reorg. It gives benefits as to what it sees are possible with such a realignment.
Vagueness is related to the wide-reaching scope of the business, and high-level, long-term goals that they don't want to give metrics for, because they'll be held to them. It's also the description of the vision people see in the future when they think of MSoft (and in turn, how valuable shares will be).
I get that there's a lot of negative feelings towards corporations around the startup scene, but if they just said "Hey guys, we're completely restructuring so our teams can focus more", people (people important to Microsoft, i.e. shareholders) would want to know why the decision was made, how they see it playing out, when it will happen, and what the potential impacts could be in the future.
TL; DR: It's a press release, not a white paper.