It would be very interesting to get more info about the US vs non-US change in subscribers. The fact that they are saying that more than 50% of the viewers are choosing the Spanish audio feed suggests that much of the growth may not be in the US.
You also currently have the Leagues Cup being broadcast on AppleTV which is a one month tournament of every LigaMX (Mexico) and MLS (USA) club with a $40-million prize pool.
My uneducated guess is that it's a mix of Leagues Cup, global superstars signing with MLS clubs, young stars such as Thiego Almada in Atlanta who just won a World Cup, and MLS beginning to overtake LigaMX in quality that is drawing more and more viewers recently - many of which are likely Spanish speaking.
I'd point toward tonight's quarter-final elimination match against LAFC and Monterrey as an example that is likely to draw a ton of Spanish commentary views.
For some reason, headlines like these always make me think that soccer’s popularity is growing in communities where it hadn’t before. I imagine it is growing, but not at the rate I would incorrectly infer from the headline. Apple seems to be betting on that growth increasing.