In my reading of current political theory there is the widely shared insight that the demand for minority rights should be seen as response to state nation-building, which is associated with policies to disseminate the majority culture (and language) throughout the territory of a given (nation-) state. Nation-building in this sense appears to be closely related to capacity building.
The normative implication is that (state) nation-building is important and legitimate but must be limited by protective rights for cultural minorities. And so is (state) capacity building. These group-differentiated rights in turn legitimize state nation-building. Such treatment should not be considered preferential, or privilege or special status. It rather compensates for disadvantages faced by minority groups that the dominant national group does not face. Among them prominently the threat of cultural extinction. And for the individual the risk to loose its cultural context to make free and meaningful choices, which is important in liberal political theory.