Of course, you realize that the lock might just result in someone banging on your door, saying "Hey, I know you're working, but I just need to talk to you a second. Can you open up?" (while you do your best to keep a straight face & listen to what a colleague is saying on your headset...) ?
So, you'll still need to work on trying to redirect people's urgent thoughts into asynchronous message formats.
But hopefully, a privacy lock will at least reduce the frequency of interruptions.
