So when you switch jobs you have to get surgery to get the device removed? I guess people will have to never switch jobs then. Sounds like a way to keep people from quitting a bad employer.
I don't see why you would have to get the chip removed. Access to company services could just be disabled.
Switching jobs would incur a slight penalty of 1) removing chip, b) re-programming chip, c) leaving chip. I think this is something a lot of people would like to avoid.
My guess is that there would be no need to remove or reprogram. I assume the chip simply presents a unique identifier and nothing more. The old company could just remove access based on the identifier and in a similar way, the new company could grant access using the existing chip.
It's a couple minute procedure likened to removing a splinter. Also, you don't really have to get it removed if you don't want to, it can be inactivated without your involvement.