Watch the video again. It's not that the tranny is cold versus warm. It's that the engine is off versus on, cycled through the gears and iding in park. That's when it takes more fluid.
As a matter of fact, if you have the engine idling in park when it's cold it will hold more fluid than idling when hot. If you fill it idling in park when it's cold and let it warm up it will continue to pee fluid the hotter it gets. You should be monitoring the transmission temperature can cap it off when it hits the proper temp. Otherwise it will dump fluid as it gets hotter and you will be under filled.