First, not every Yue speaker speaks Mandarin. Second, the fact that they also speak Mandarin (because it was a mandatory lesson at school or they were otherwis

First, not every Yue speaker speaks Mandarin. Second, the fact that they also speak Mandarin (because it was a mandatory lesson at school or they were otherwise forced by circumstances to learn it) does not mean there should be no support in Translate for their native language, which incidentally dwarfs many languages that Translate does support in number of speakers. If you think that’s viable logic, you should try applying it to other languages with predominantly multi-language speakers. Start with Irish (98% of people in Ireland speak English, after all) and move on to Catalan, see where that gets you.