Re: And here it comes
I've been saying this for a while too. But I don't agree with your conclusion. Microsoft is at the end stage of revamping its business model. Once all those "legacy" products are out of support:
If you have some kind of enterprise agreement with all your servers and desktops and client licences, then you are a customer. You have no choice but to renew.
If you have an Office subscription (cloud or on-premise) then you are a customer. If you want to continue to use it, then you have to continue paying.
If you use any of the "cloud" offerings and are paying for it, then you are a customer.
If you have Windows as a result of buying new hardware that came with Windows 10, then you are a prospect. You are only interesting to Microsoft as you might sign up to one of the above.
If you have an older version of Windows or you took the "free" upgrade and don't fall into any of the categories above, then you are not a customer. You haven't spent money with Microsoft, You are unlikely to spend money with Microsoft. Microsoft does not care about a tightwad like you (me!).
So, the final question is that out of those "billion" devices now running Windows 10, how many are covered by the above agreements and is it worth setting up a subscription option for the remaining devices. Or is it enough just to force feed the maintenance updates to those users first so they can find the problems in advance of paying customers?