What, really? Your source is "some Czech guy?" I mean maybe it's true and maybe it's not, but at the same time an article that presumably doesn't link the original article because they don't want people just going directly there and which might be quoting the most lunatic fringe conspiracy theory is not worth taking particularly seriously. A five-minute search tends to indicate that this guy:

https://systemoverlord.com/blog/2015/08/16/so-is-windows-10-...

hasn't been able to reproduce the traffic analysis on casual inspection.

Edit: Here's what I believe to be the original source of the claim:

http://aeronet.cz/news/analyza-windows-10-ve-svem-principu-j...

And the translation:

http://localghost.org/posts/a-traffic-analysis-of-windows-10