It's definitely Chepo's fault for playing favorites. He singled out Vela for not playing when lesser players were in similar situations and still getting call ups. Not to mention he got reprimanded for that incident in Monterrey and received a more harsh punishment than everyone else.
Of course, now that Chepo sees that he's playing well, and he's struggling with the same tired tactics, he wants Vela to come to the rescue. He ends up trying to talk to him and ends up not calling him up because Vela wants to play the last game of the season, which could clinch a Champions League spot. But Chepo decides that it's considered special treatment, so he decides not to call him up.
Meanwhile, Gio ends up playing with Mallorca, he will go on a private plane to Houston to catch up with the team, and no one says a peep about "special treatment". So yeah, Chepo bug his own grave there.
Anyway, obviously I want Mexico to do well in qualifying and in the Confederations, but I won't lose any sleep if they play like they have and he gets canned. I'm confident that the problem with Vela is squarely with Chepo and he will accept another manager's call up.