The way Arma 2 handled kicks because of Addons has been lost in Arma 3. This is by FAR the most needed feature in my opinion for a game that runs primarily off of mods. To have to check the RPT anytime we are kicked from a server because of a missing Addon is time consuming. Not to mention most players don't even know where or how to check their RPT for said kick reason.
My hope is that this notification will be added back to Arma 3 so that anytime you are kicked from a server due to a mission addon it will atleast have a popup as to what you are missing.