Regardless of using the start menu or not, there's a lot of background tracking (for user behaviour and ads) that needs to be disabled by registry edits. In addition to those, there's probably more that cannot be disabled.
What I don't understand about this, however, are people being paranoid about W10 while they're happily accepting Google and friends to infiltrate their lives ¯\_(ツ)_/¯
You are of course exempt if you don't use any cloud-based services that you don't host yourself :D
That stuff also has a nasty tendency to ""accidentally"" get re-enabled after updates from many reports I've heard.