I agree with you that beating Benavidez is just frosting to an already enormous cake. I don't understand why some people act a win over Benavidez means all that much. Canelo has already beat fighters who are far more skilled, far more talented, and far more accomplished. Is Benavidez the fight for Canelo today, sure, he's already cleaned out 168 of all its champions and a few top contenders. But to act like Benavidez who's best win is a decision win against a fighter Canelo KO is comical. As far as fighting Benavidez in September, it's highly unlikely since that's exactly three months after Benavidez fights at 175.
Benavidez has missed weight multiple times and has allegedly weighed up to 195lbs whilst fighting at 168. I'm not sure if heart has much to do with his decision to move up.
After Morrell, Canelo would retire. Because he's getting knocked the **** out. He's always had issues with small slick featherfisted southpaws, do you think that's going to improve against a massive heavy-handed southpaw?