> The telemetry in Windows 8 was just in critical components that had been instrumented long ago, such as Windows Update, crash management, etc. None of those were using the current universal telemetry system.

Are you sure? I did a lot of Windows 8 installations when I was evaluating it, and I distinctly recall the option to turn on the same tracking features that 10 had on by default. In the Windows 8 installer they were presented up front and off by default, in 10 they are hidden and on by default.

As of a month ago this is still the case; I reset a Windows 8 hybrid laptop, going through the standard installation screens, and then upgraded it to 10.