Just the very tweet that is the topic within this thread. The last time I'm aware any President said anything concerning the operation of college football was in the days of Teddy Roosevelt (risk of injury/death in football).
Unless you count Nixon chiming in on who should be named National Champions.
And Trump said this for one reason - to get Big Ten football fans within the light bluish or purplish states to vote for him. He thinks getting football fans in those states to love him for "getting football back" will make them sweep out in droves to vote for him. Several key states that are in play are in Big Ten Country (Michigan, Pennsylvania, Ohio, Wisconsin, Iowa) and he needs to either shore up a small lead or make up a small deficit in order to make sure he gets those Electoral College votes. That is the only college Trump cares about.