Lol, there's this thing called video editing. You know? You can pre-record a battle and then, later commentate over it. Also, given the questions I've received on EBS from these guys, I'm highly sceptical that they have the technical prowess to script that. Also, might I add, were this really an AI vs AI battle, the command windows on the player's side would not show up.
There'd be no easy way to go about doing that. You'd first have to make a dummy battle instance, and bypass the command and fight menu phases on the player's side, and depending on how smart you want your AIs to be, implement an algorithm that would favour certain moves over others, based on the current situation. I doubt there is a "do A then do B" method to this.