I think they (Fury and Joshua) owe it to the sport that butters their bread, at this point. When is the last time all belts, including lineal champ, were unified? I believe it goes back to the Tyson/Holyfield/late career Foreman era, but I could be wrong. The heavyweight division has been effectively nonexistent for over a decade, in the MMA era. Fury, especially, could be the champ that brings the spotlight back to the division, and sport.