I live in Taiwan and we have here the same problem, the official language was first "Japanese" when it was a Japanese colony and then mandarin Chinese when Chinese "invited themselves" to Taiwan, declared martial law and that official language would be Mandarin.But More than 70% of Taiwanese people speak Taiwanese(hokklo) and about 3% another language ( aboriginal and foreigners).
Old people very often can speak only Japanese and Taiwanese and can't get a word of the "official language".
The "elite" wants kids to get better in Mandarin, kind of paradox when you know that in China (PRC) itself less than 50% of the population speaks Mandarin...