Well, I'm from Latin America, Uruguay to be more precise, so I should be playing on Brazil.
The thing is, I play games since I was a kid, I started in online games at the age of 11. I know how the people on the brazilian servers is, I play CS:GO a LOT, and, honestly, when I bought Overwatch I decided to find the way to play in NA. I found the way, and since day 1 in OW I'm always playing in NA... I NEVER use spanish in chat or voice chat, I always use english.
It's common sense, you want to communicate with your team, you MUST learn the language of the server.