I suspect they should say "this machine is not confidential" and have good reasons for that - you can't just impose extra restrictions on your employees just because you want to.

The law (as executed) will weigh the normal interest in employee privacy, versus your legitimate interest in doing whatever you want to do on their computers. Antivirus is probably okay, even if it involves TLS interception. Having a human watch all the traffic is probably not, even if you didn't have to intercept TLS. Unless you work for the BND (German Mossad) maybe? They'd have a good reason to watch traffic like a hawk. It's all about balancing and the law is never as clear-cut as programmers want, so we might as well get used to it being this way.