That's actually pretty intense for Chavez' training standards we're talking about a guy who prepared for the biggest match of his life by getting stoned and training in his living room
Unlike Loma, GGG has plenty of power to carry up a couple of weight divisions. Moreover, unlike Loma, GGG routinely spars with guys LHW and up, so he's comfortable in the ring with big guys. Lastly, weight differences account for less of an advantage in the higher weight divisions then they do at feather weight. Let's say Jr comes in at 187 after making 168, and GGG comes in at 176, that 11lbs isn't going to mean as much at SMW as 11lbs does at FW. In other words, GGG doesn't have that excuse, and anyone using it is really just making excuses. It simply wouldn't be a legitimate excuse for GGG, and I don't think fighting a bigger guy will be much of an issue for GGG in this case, even if Jr. comes in with a 16lb "advantage."