It simply disables PB. It does so called "Turn it off". And when an update occurs, it updates before PB even kicks in, so that is not an issue.
A PB bypass CAN BE safe if you use an undetected one. They don't tend to disable/shut down on their own unless there was bad coding. A good working bypass that won't be detected for a while can be hard to find sometimes. If you can find a trusted one, then good for you.