This, in a machine that's been designed for generations to have a fan pull air aggressively THROUGH a channel, the only path the air can go, that goes directly across the CPU heatsink. This is not a 'circulating the air' situation: a laptop can't do that. It's an overall system with many considerations (turbulence, air handling noise) that is no longer a system at all if you take the top of the duct off. You cannot run that sort of machine with the case taken apart, it's part of the ducting.
Either he's dishonest for effect (and clicks), or he's considerably dumber than a drummer and college dropout (yours truly! derp!) about cooling airflow in a constrained duct inside a laptop. At face value, he's dumber. For his sake I hope he's dishonest.