I think the problem is that you want to do it with the command line. In ML it was possible to truly disable the Notification center by renaming a core system software component, but in Mavericks that same solution caused problems. However, Apple added a method of effectively disabling all notifications by using the Do Not Disturb function in the Notifications portion of System Prefs (set it so that notifications are only active for one minute during the middle of the night and you'll never see notifications again unless you happen to be using the computer at that time). Possibly you can find a way to set the Do Not Disturb preferences via a command-line function. That wouldn't exactly perform the function you wish, but it's a reasonable work-around. Otherwise you'll be left to set this function on each machine manually.