I am not sure that charity is the Big Ten's sole motive in featuring TO as a "Big Ten Icon." Part of bringing Nebraska into the Big Ten was to raise the conference's profile. You've now got four of the top 10 winningest programs (Ohio State, Michigan, Penn State, and Nebraska) in the same conference. That's more than the SEC (3), the Big 12 (2), or the Pac-12 (1).
What better way to further the goal of raising conference prestige than by laying claim to one of the winningest coaches in college football history? It is a subtle way of saying that TO is just another in the Big Ten's line of major figures in college football history (Woody Hays, Bo Schembeckler, Joe Paterno, etc.).
Calling TO a "Big Ten icon" is a two-way street: It says, "Welcome, Nebraska!" and "We're the best!" all in one breath. The technical term for this is "win-win."