NFC RFID badges have a range of 10-20 cm. Unless an employer is requiring badging in and out of the bathroom or is using UHF RFID badges (is there even such a thing?), your assertion is unlikely to be true.
When I was a consultant I visited many offices where I needed a badge to go to the loo. It's really common in shared office buildings, the toilets tend to be in the elevator hall outside the badge perimeter. Don't think they were monitoring it though.