Do you know that for certainty? They could very well check from time to time if the internet was reachable and then phone home, else do nothing. I think people are making all kind of wild assumptions based on hot air.
We shall see won't we? There are many environments that will not allow for networked PCs. If they can't upgrade, or the software completely craters because it can't phone home, this is going to make for some interesting negative PR for MS.