Bullshit. Versions of Windows that are all labeled Windows 10 are running in a lot of devices, and you can write applications that in theory can run on all of them (though practically writing one application that runs well on all of them may be somewhat harder if you want your application to be useful in any way.)
But that is NOT the same as "Windwos runs everywhere." in a number of ways.
The first and most obvious way is that you can't just take your existing Windows application and put it everywhere, which is what that phrase seems to imply. Nor can you buy one of these devices and immediately have access to all the library of millions of Windows applications that exist. No, if you're a developer you have to write a new universal app and embrace the Windows 10 App Store whether you want to or not.
And if you're buying a device, you better check twice that the software you want is available for the platform you're buying lest you find out too late your device has special requirements.
Secondly, we've had a version of Windows running on lots of devices for a long time. The only thing that's different now is the branding. They're finally all branded "Windows 10" even though in many cases (like Phone and X-Box One) the user and developer experiences are totally different. Is that helpful? I don't really think so.
This article might as well have been written by Microsoft's PR department. Totally not grounded in reality at all.