The article links to this page, which was shared on HN yesterday. [1]
I feel like using wireshark to look at what's being sent back and forth from Windows telemetry, when using Edge, Chrome & etc should reveal what's being sent and recieved. Using MITM SSL spoofing should be able to intercept the packets.
I would be shocked if Microsoft was not using their own layer of certificate-pinning to stop people from doing that, and/or using another layer of encryption separate from the networking layer.