A good idea to my opinion, when you are away, set a message saying you are currently not available and will return their messages/calls as possible.
This should be added and should probably be hooked into things like Microsoft Flow as well
+1 on this. Need ability to tell people off without shifting focus, but leave a nice message stating we'll get back to you. For when you are present, but not available.
El Solitario commented
I think that's a great idea, but it could be allways when you want, not only when you're away.
For example, I work with virtual computer in full screen. I would like to set an automatic reply when anyone write me a message in the Skype installed in fisical computer.