I tried providing a start today in your previous post - Volumio and privacy.
I agree this information should be explained better, and available in an easy to reach place.
This is a good start – but I think having a Telemetrics/UI stats Opt-in/out the first start wizard would be the most transparent way forward.
For example, there is no current way to disable calls to a rather ominous sounding http://updates.volumio.org/downloader-v1/track-device