I think Microsoft is aiming to unify their platforms a bit too early..... the reality is also that beyond Windows for computers, people don't reall like Windows operating systems (tablets / phones /etc.)

just looks desperate, they have lost money every generation in their video game division so at this point are trying to merge some of their video game division (if not at all) with their successful business side (computer software)

Microsoft has lost money for every video game system they've put out hahahahahaha. They just want to have branding influence

They don't have the leading operating system because that's what consumers want, that's a total fallacy. They have the leading OS because they were first to mass market and essentially created the PC as we know it. Now they hand out free copies and beg old users to upgrade, and then go and brag about how W10 is installed on x number of hardware. Simply, other companies beat them at their own games these days on just about every front and it's rather apparent by their often reactionary, poorly thought out decisions and when they do try to innovate, it doesn't work out. The latest example being "we support AR, not VR, and there will be games from this technology, on xbox". Well, they quickly started back pedaling when it became obvious just how much hype virtual reality was generating. Mark my words. Holo lens will never come to Xbox now and they will soon announce a "me too" attempt at supporting VR. They have no back bone as a company and I think a lot of consumers see this, though they may not entirely understand. Microsoft is losing ground on all fronts except productivity and cloud services.

And don't kid yourself. They've been leveraging their OS since the original Xbox. Wanna know a more accurate name? DirectXbox. Uses the same proprietary technology and their consoles have always been based on Windows. This gen they're just trying really hard to bring attention to insignificant factors. I'm curious what an Xbox can do for me as a gamer (or even consumer) that a ps4 can't. 

Microsoft to take over gaming?

UWP is the right thing to do for MS, they have one of the most used and complete API, direct X, a stronghold on PC, they now have a common platform, so definitely that can improve their shares in gaming, or create new opportunities.

But I don't think it can have a tremendous, immediate impact. they are currently not growing on their strongest markets (console and OS), challenger on others (smartphone, tablets, but also universal API, and Store) and whatever the universality you provide for your binaries, API, and store, at the end of the day you have totally different constraints on each device : length of gaming session, controller, screen, power, battery if any.

It's not by accident there is very few games that have been successful on that different devices. In fact I can think of only one, Minecraft, perhaps that's why spent so much on it.