"Mispronouncing" to your phone's language is actually helpful if you don't speak the language, because you'll legitimately understand it better. Local pronunciation can often be completely and maddeningly unrecognizable to a foreigner.

While if you speak the language, it's obviously nonsensical to have it mispronounced and you want the real thing of course.

Example: "Rio Tinto" in Portuguese is pronounced "HEE-oo CHEEN-too". If you don't speak the language, you're NEVER gonna map those sounds to a street sign because the "r" and "t" sounds you're expecting aren't there at all! While hearing a completely incorrect "REE-oh TIN-toh", you can probably recognize.