here is good explanation
I know some will disagree with this, but personally I find this post on ArsTechnica forums (not mine) to be the best explanation of what's going on:
This has nothing to do with Microsoft being unclear. If anything, this is the press (and I'm including you, Peter) shaping the discussion into something that was never explicitly stated.
Microsoft starts the discussion from the assumption that you are a legitimate, licensed user of Windows. In that context, they have been crystal clear: If you already upgraded as an Insider user, you will get the update and remain genuine. It's a continuation of your existing status. That's reasonable and consistent with what's gone before.
If you don't have a legitimate ("genuine") Windows license, Microsoft isn't talking to you. You are not their customer. You have no relationship, status, contract, or claim. You might find a work-around, or a nudge-wink activation process, but that does not mean you get "genuine" Windows for free. Technically being able to install it does not mean that contractually you are legitimately licensed. Also consistent with everything that's gone before.
The trick to understanding Microsoft's communications is simple enough: Listen carefully to what they say, and assume the narrowest possible definition. And what they don't say is just as important as what they do.