Canelo gets better after his loss to Mayweather, he learns his lesson and he trained harder. In fact, if Canelo and Mayweather will fight now, I believe that we will see the opposite of that fight, and though Mayweather is very slick, I'm pretty sure Canelo would hit him and would probably knock him out.
I also believe that. Canelo already matured after that loss from Mayweather and the same perceptions if they will fight again I'm pretty sure that the outcome is different, Mayweather is good but seeing how Alvarez adjust and keep winning his fights that would be a big difference if chance gives them that rematch.
Moving back to this upcoming Bivol fight, we will probably see the adjustment since he will be facing a much bigger and stronger opponent.
Yes, we can expect an adjustment from him, however, Canelo is not afraid of fighting a taller and bigger fighter as he already beat a lot of fighters like that in the past. He might not able to beat them in the early rounds but with his maturity and ring IQ, his strategy is slowly but surely so in the end, his opponent will be gas out because of the consistent power punches they will receive.
Canelo's advantage against taller and bigger opponent is his speed, so he still have an edge.