Two Gold Cups weren't sufficient to settle the question of who CONCACAF sends to the 2017 Confederations Cup. There must be CONCACAF Cup: a winner-takes-all playoff for the right to get an early look at Russia's 2018 World Cup facilities.
It is always enjoyable to see the region's two heavyweights go head-to-head in a competitive game, so perhaps it is best to shelve skepticism about CONCACAF's true motivation for this fixture ("Is there any way we can create MORE sold-out matches on US soil?"). The stands will be full, the teams should be able to generate some intensity befitting their ongoing rivalry, and the result does matter - Confederations Cup may be, essentially, a friendly tournament, but it is a useful element of preparation for the World Cup.
One suspects, however, neither team will be able to celebrate a victory for very long. Jurgen Klinsmann increasingly can do nothing right in the eyes of the US soccer media. His methods are well established, and the argument in some quarters is with those methods: results aren't really the point of the criticism, though a bad game certainly helps the critics to amplify their voices. Whether his team wins against Mexico or not, Klinsi looks stuck with a relatively hostile press - and riled fan base - for the foreseeable future.
And, in fairness to the purveyors of that hostility, Klinsmann has so enthusiastically embraced the freedom to experiment afforded by the start of a new World Cup cycle, it is very difficult to determine what his longer-term plan might be - so the chorus of disapproval is filling something of a vacuum with regard to any sense of continuity or consistency emanating from the USMNT.
Meanwhile, El Tri is poised to appoint Juan Carlos Osorio as its head coach for the upcoming World Cup qualifiers. Therefore, a victory in this game doesn't tell us anything about the squad's momentum or tactical approach heading into November. Win or lose, the next Mexico squad we see will be under new management, and the process of second-guessing managerial intentions will start anew (and that is a wild ride with Osorio, his recent successes notwithstanding).
So this game is perhaps best taken for what it is: a clash of CONCACAF's titans, a day out for their respective fans, and a chance for one to get part of its 2018 World Cup preparations scheduled well in advance. The calls for Klinsmann to be fired will continue, regardless of the outcome; there are plenty in Mexico who think Osorio should not be appointed at all. Both winner and loser will head into World Cup qualifying with questions to be answered - mostly posed by their own skeptical fans.