Re: It's a conspiracy
>Do you seriously think that MS is going to install W10 on legit W7 and 8 machines without telling anyone?
Obviously, you didn't have to deal first hand with the mess created when MS initially 'offered' the Win8.1 Update (via the Store) to Windows 8 users (using a "Get Windows 8.1" app that had been downloaded via WUP and then put the update natively on WUP for all those still running Win8 and thus catch out all those who had ignored the "Get Windows 8.1" app.
I suggest this effectively was a trial run of the "Get Windows 10" app.
I also note from this article and the articles it references, MS are not distributing anything that easily disables/removes the "Get Windows 10" app (eg. a "hot fix") that an administrator/IT expert could easily deploy across an estate.