Nonsense, I live in Mississauga and we don't have silos of cultural groups who don't speak English. There is no Chinatown or Little Italy, and even those that do exist in other cities  represent a very small percentage of  immigrant populations and most people who live in them are perfectly capable of speaking English or French, especially the younger generations.  

When I was in high school I had many friends who were first generation Canadians whose parents immigrated from Italy and Portugal. While often the mothers & grandparents didn't speak much English, the fathers and the kids certainly did by virtue of going to work and school. By the following generation everyone spoke English. How do you not learn the prevailing language when that is the language of school instruction?