The IFE system has ties to the weight on wheels sensors at a minimum, meaning a ground test isn't a faithful reproduction of an air test. (That's how the IFE shuts down at touchdown, and I suspect it's how they know to push you their takeoff ads.)
Delta's system plays the Delta ad while the aircraft is still over the runway on takeoff and the entertainment shuts off in the first few seconds of rollout, as I recall.
I'd be surprised if there's a flight attendant whose duty it is to hit a button at a critical time in flight to make that happen.
