I think there should be an official language but there should be translation services available to ensure accessibility. I think it should be encouraged to maintain one's culture but to also learn the local culture both. No reason you have to sacrifice one for the other. I like that I can walk outside and hear like 5 or 10 different languages just by going on a walk, but its important to have a basic common language as well. Of course the common language can change over time as is needed if one language becomes the majority spoken.