Earlier quoted context omitted.
A laptop is a great substitute for a desktop if you have a dock. I just place my laptop on the dock, it clicks into place and I have a couple of big screens, a full size keyboard and a mouse on my desk. No different than a desktop.
The article is discussing mobile desks, so to get the benefit you are describing you'd have to have docks, monitors, and peripherals at every workstation.
The office I work in, everybody gets a door. With all the arguments about economics, I think some people don't experience the same value to closing the door and working uninterrupted for three or four hours every day. I'm certain whatever the walls cost here, it's small compared to the productivity gains.