I don't find it surprising that release candidates for an operating system are heavily instrumented. The goal of a release candidate is to find problems that didn't surface in the alpha and beta testing stages. Those will tend to be subtle corner cases.

Going further, phoning home is industry standard these days. Not just for Google or Apple operating systems but even Linux distros: e.g. Ubuntu.

I'm not saying it's right, just that it is not unique to Microsoft.