Office for iOS: 365 only?

So the big question lately is whether Microsoft would release Office for iOS with the debate being whether or not they want to potentially cannibalize Windows (especially RT) tablets in order to tap the existing iPad market. So with the way they're moving with 2013 and pushing 365 over the traditional boxed versions, I was thinking the solution would simply to make the theoretical iOS version 365 only. The apps themselves would be free downloads but they wouldn't actually be functional without a 365 subscription. They can then tap the market in a way that fits their new "Office as a service" focus, but also doesn't take much away from Windows' competitive advantage since an RT tablet will still have the apps bundled and you can use them standalone without having to buy into a 365 subscription.