I don't see that the language used at home necessarily matters, providing that they're able to speak the national language fluently.
There is a issue with some older Muslim (primarily Pakistanti) women in the UK not speaking English well, because it limits their ability to have an active life outside the home. There's no issue with a kid using Urdu at home and being fluent enough to get a GCSE in it - it's functionally the same as white couples who bring up their kids to be bilingual, which nobody has an issue with.
In America, the English language requirements for citizenship have been widely derided by left wing activists who insist a bilingual society can function just as well as a society where everyone speaks at least one common language.