Canelo doesnt need to acclimate to the full MW limit in the sense you are suggesting, because he has fought above the MW limit.
The fight was made because the Mexican public demanded it. Canelo would be foolish to pass up on a MEGA payday like that. Hardly a real fight.
Typical ASSOL...stuck on the words of posters he cares nothing about, nor respects. This is why you haven't grown once since Coming here as a 13YO odlh nuthugger. You prefer to delve in to this stuff, since it's what you're good at.
If it wasn't obvious for you that Canelo was smaller than GGG when they fought You should try watching actual fights, you may learn something.
Amir Khan weighed in at 155 the day before he fought Canelo , it doesn't mean he's bigger than the Lara's and Charlo's etc. GGG is a natural MW who fought there all his life , Canelo moved up to MW , he's clearly the smaller man.
You're right in that his body will certainly be more acclimated for 160 but I'm not sure how much difference it'll realistically make. He's fluctuated between weights for most of his career without his stamina changing a whole lot. I've certainly not noticed much difference in the way he fights at least, so yeah I don't think it'll change much. It certainly won't make him worse, that's for sure.