Both dudes looked weathered. Definitely not used to seeing GGG be that gun-shy. You're right about Canelo and Bivol too. Moving up in weight and taking shots that you can't get out of the way of while the other dude makes it look easy can be taxing physically and mentally.
Canelo is tough as hell and has a chin, but I'm a firm believer that you can get into certain fights that take something off of you no matter how strong your will is. After not looking like his normal self in this fight and then taking some time off it's going to be really interesting to see what his next move is.
And for GGG, I'd rather see him hang them up sooner than later rather than sticking around.