Among the non-shills of us who actually are capable of independent thought... what you describe is a possibility, but probably not a likely one.
Can a phone do everything that a desktop can? Usually not, so doesn't it make sense to tailor the version of an operating system for a given device?
Microsoft has sold different editions of Windows for years, each with different or overlapping checkboxes on a feature matrix. A device running a 'Ultimate' edition will probably have different capabilities of a 'Home', and an OEM who sells you a tablet, laptop or phone is going to put a given edition on it which will give you those certain features. I'd bet good money that is what they are referring to... an idea that is far more rooted in reality than anything you've said here.
Hell, for quite some time there has been the ability to upgrade from one edition to another for a price (though I've never met someone who has done so). That upgrade is permanent... or can you point to people being automatically downgraded because they failed to pay 365 days later?
Hell, when Windows 8 first came out there was a way to get free keys for Media Center for the first year... guess what? Media Center still works here several years later, I didn't have to re-up for year 2 or 3. Odd that?
Your paranoia does not seem to be founded... or would you be willing to cite some specific examples and not paranoia (or hate) induced hypotheticals?