Weight-wise, I don't see what the big deal is with Canelo weighing in at 152. Unless there is a viable source that directly confirms that he is tight at the weight, I'd say he seems quite fine.

For example, appearance wise, him and Mosley were the same size (Mosley and Mayweather were also the same size!) and Trout was far from dwarfed by Canelo, in fact I'd say Trout was bigger.