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.
I’m trying to understand the GDPR equivalent of this, which seems to exist since every text fields in a database does not appear to require the full PII treatment in practice (and that would be kind of insane).