Nintendo is stupid to do this. Those videos (I don't watch them or care to) are advertising for the games. People see them and go hey I want to check this game out.
If you start taking away the incentive to make those videos which advertise your game to people who might not really have liked the game but then saw the video and decided to buy it they will simply stop making those videos.
So Nintendo you don't get the ad revenue either way but you do get the additional sales of the game that might have been missed.