It was only used if a staff member was suspected of something, it's mostly for litigation and customer theft, no one actually watches them, they just record all the time. But the same cameras can be used to track interactions between a covid positive staff member, other staff or customers, so its no overreach. I'd say most airports would have CCTV operating especially on RPT ramps and such, just matter of whether they want to share the footage with companies, I know it has been used by companies to check on staff before. Big brother has been watching you for a long time now in almost every industry. Any time you enter a pub, club, supermarket, petrol station and 99% of shops you should smile for the camera. Plus now you can almost guarantee at least one house in your street to have a camera pointing out to the street.
PS if you are going to retort with this being something new and dangerous, its been this way for 20+ years. Just the technology has improved greatly. The big brother arguments flew the coop pre-2000s.