My vote goes to the “Org Too Big, Nobody Cares” explanation. Or, perhaps, just the blissful America-centric ignorance about how there are regions in the world with multiple official languages. Haven't checked this recently, but a while ago Google Maps was still serving street names in a random language (the first name in alphabetical ordering), for streets which have names in multiple languages.
We have two official languages - Finnish and Swedish, neither of them big enough to warrant any Google effort for proper text-to-speech. Hence, the voice navigation first pronounces street names in Finnish, then again in Swedish, both butchered by applying English spelling rules, all voiced by an extremely robotic voice