Jesus. Thats a one note offense. Mexico ain't got no need to even worry about the right side.....or anyone except Coutinho. Just let Neymar flop and dribble on the sidelines for 90.
I think the problem South American teams and especially their fans and media have is they're stuck in this '80s mindset where it's all about giving the ball to the number 10 and expecting him to single-handedly beat five defenders and score every game, dragging them to the World Cup. That's outdated and in order to progress Neymar has got to be just another player instead of being the god of Brazilian football.
That being said, Neymar and Marcelo have a fantastic understanding and link up really well on the left flank. Filipe Luis is pretty good too from what I saw. So it might be in Brazil's best interests to focus their attacks on the left and refuse the right flank. Willian is a decent player and an honest worker but he's no Douglas Costa, and if he can't be picked for the next game then it goes against Brazil's strength to start focusing attacking on the right flank. You play to your strengths.
The same goes for Fagner too, he doesn't look super impressive going forward. So neither at right back or right wing do they have any really top quality attacking players. It's better in that situation to go left and have the right just hold their line, find space and wait for the switch or the cross to the back post.