His revenge from that first fight lost? It makes sense so that if cotto beat trout impressively better then canelo did then it makes more sense for Floyd vs cotto rematch to happen or a canelo vs cotto so that if Floyd beat a new improved cotto, nobody would discredit Floyd win or if canelo beat cotto, nobody will say canelo beat a shot decline fighter. Too me it's better if cotto face trout in a rematch and proved if he's really back to an elite status.
i know it would look good on resume but in life it would be a backward step for cotto at this time..he doesnt have much left so they want the best options out there imo. trout is little reward now without a belt that cotto was going for.