This is a one paragraph claim that doesn't provide resources to show that their claim has basis. It could very well be entirely accurate, but there's no information contained here to know one way or the other.

For example there have been numerous claims made previously that link ANY network traffic to a supposed invasion of privacy, but once you delve into the underlying traffic it isn't nearly as nefarious as it initially seemed.

This article is telling you to "open up the network monitor of your choice" but network traffic and CONTENT are apples Vs. oranges, and yet we're meant to draw conclusions from that? We're meant to know Microsoft are taking your slide's content whole-hog? Isn't that yet to be determined?