I don't think they will be getting rid of being able to buy and own windows any time soon. We will continue to have our local installed and owned versions of windows for another decade or more.
If anything this is MS gearing up to combat Chrome OS. MS needs a Chrome OS style of OS that is easily managed via the cloud for mass deployment. One of the biggest reasons why Chrome books have taken a liking to schools is the fact they are easy to manage as a whole.
Honestly I've been expecting a Cloud based windows for a long time now. MS is behind on this. Add it into the 365 suite and schools would easily move back to MS. I've used google Doc's, it sucks. Honestly would rather use Office online. MS is missing out on yet another cash cow.