I’m José from Mexico and I just saw that early today Apple made the TV app available to mexican users in the Apple TV. I have been using it for the last hour.
The app is just available for the Apple TV and it still doesn’t show on the iPhone or iPad (in both of them the Videos app is still there). I’m running the latest public beta of tvOS 11.3. I’m also running the latest betas on my iPhone and iPad.
The available apps that work with the TV app in Mexico are: Clarovideo, Amazon Prime Video, PlayKids, HBO GO, MUBI and Las Estrellas.
Here are some pics I took from my screen using QuickTime on my Mac: