Actual football ("soccer") really works on the majority of the world. Fewer equipment costs, constant action, tantric scoring, and just enough simple subtlety in game design that people on all ends of the productive intelligence spectrum can have a valid opinion about what is happening or has happened. The television-focused American game ("American football") has been attempted in other places, with its inundation of marketing breaks, and its African-specific skill sets performing specific useful functions in America, yet, from a marketing standpoint, these functions will not translate into future demographics. What interest will an un-guilty Hispanic United States, whether short or mixed, have in a sport highlighted primarily by tall, large Africans running around? Some, but not comparable to the interest Nu Euros have shown in watching Nu Euros strategize how Africans should move or not move. Future demographics will demand American conformance to the chariot races already proven effective even in Asia, where it is possible for full mixed-race teams to compete in a global fashion.
(Like movies, professional sports, and television shows, a diverse cast can also help ease the transition to more diverse societies.
Contemplate, e.g., a future Zuckerbergish Chinese elite using "our last loss at the Cup" to justify importing "just a few potential players, a small test group really" then a managed win or two attributable not to the refs but to the imported players, to crack Asia open.)
Will they replace American gear-mashing with global ball-kicking? Some American Hispanics are really into the NFL, but the apparent minority-exclusivity of its Afro-Americanization has played a part in that, and it seems unlikely that a sport based around staggered smashing will consistently appeal to targeted future consumers. (With heavy investment and market monopolization, it could, but we've already seen that fail and the market purchases more on football.) The rest of the North American continent, to say nothing of anywhere else, seems disinclined to prefer gear-mashing--even based on a tenuous connection to a more mental Euro-strategizing competition--to constant ball-kicking. Producing exciting rhetoric to explain staggered gear-mashing grows less effective each year, while the constant action and rhetoric of play-by-playing a football ("soccer") game is quite different.
("Baseball" will still exist to distract those who want to pretend at intellectuality, as we've seen in Japan. Baseball and football may prove more enduring products, with baseball the junior partner, to keep both larger groups of consumers intrigued. American handball/carryball ["football"] is a hybrid of faux-intellectualization and spurt athleticism that only had a short lifespan as a product. Much as Europe may require a mythological Arab MLK, or America a Hispanic one, American carryball's working life seems to be drawing to a close.)
Europe, though not yet Asia, has certainly shown that mixed populations continue to respond better to football than to American gear-mashing. Afro-Hispanic teams cuts down on the Afro-exclusive nature of American professional sports, which will be necessary with future demographics. In a hypothetical NFL future, mixed Arabs and Hispanics, not to mention the Chinese, would have to watch NBA or NFL matches which are tragically regional (once U.S. hegemonic status becomes more formalized and less real), and which include primarily opportunity for African stardom. The size and speed of the African, so useful in prepping twentieth century America, will likely not provide appealing purchase- and vicariousity-models for 5'5" Indio American consumers, or 190 lb. Arab European consumers, in some number of years.
In this light, allowing African-focused American sports to gloriously diminish is an effective move similar to anti-tobacco campaigns (see A Short Chronology of Reverse Psychology in Recent Advertising). In a hundred years, smaller Nu Euro populations may fiercely defend their continued association with an NFL which stands opposed to the globalism of football populated by mixed everything. Future nation-state changes could even see a glorious sequence of potential, then actual Chinese victories, Euberian reclamations, et cetera, seemingly validating the world's material defiance and perceived skill sets. Everyone will have someone with whom to identify, and the plausibly versipellous nature of the "star" will make entertainment a shared, global experience in a way that movie saturation alone cannot.
Evaluating television strategy, perhaps a few highlighted "financial losses" for some foreign team owners will make even nationalists start to support whatever the next chariot race is, as though a rebellion has partially succeeded and everything has changed; as though watching people talk and/or run around somewhere was ever a wholesome activity. Like voting for the game-show host, professional American sports have a lot to offer in redirecting what Nu Euros might otherwise do.