I agree, and it seems that Canelo will still be the favorite no matter who is he going to face maybe against Beterviev. I understand that GGG shot might have a little chance because they are going to fight at Canelo's territory. Nevertheless, I will say that GGG is a live underdog, and simply will give his everything to win in this fight.. So yeah why not bet on him even for just a medium money, I guess it wouldn't hurt.
That shouldn't be a big problem and disadvantage for GGG. As long as he will do his best, making sure that most rounds will win by him, judges might not influence the score cards. That's what happen when Dmitry Bivol won even if their fight was on Canelo's homecourt advantage. It's hard to give a win to the one favored if the whole time, the Favorite is clearly losing every round.
It needs to be very compelling though to make the judges score the round for GGG, otherwise if it is very close, I'm seeing the same thing over again, judges be biased on Canelo.
Like Bivol, GGG has to do something to make Canelo disappointed again while fighting. That's the time Bivol crashed Canelo because the latter wasn't able now to focus on the fight out of frustration made by Bivol. GGG knows already some strategies to beat Canelo and will just wait for the perfect time to land those against Canelo. This will be a GGG win and a good timing to announce his retirement.
They have fought 24 rounds, so for sure he might have an idea on how Canelo fight. In the Bivol fight though, Bivol was able to get back at Canelo with his superior jab and his physical advantage, (height and reach). GGG doesn't have that much advantage so it's going to be the old hard fought rounds and needs to outland Canelo.