Whatever the trend, I don't think there are in Toronto, besides Chinatown which is from the 50s, enclaves occupied by very similar demographics for multiple generations (say an ethnic enclave that hasn't changed demographics for 50, 60, years or more, but of course when you go that far, Toronto wasn't as diverse to begin with). Nearly all the earlier waves of immigrants have already suburbanized or taken paths away from the neighbourhoods they first settled in. This is different from African American segregation in northern US cities that arose from a history of force not choice (it was surprising/shocking to me that Chicago's racial segregation of North being white and South being black was already in place when the first Great Migration started over 100 years back; I can't imagine any neighbourhood having the same segregated demographics in Toronto as they did 100 years ago since our earliest Black, Jewish, Irish, Chinese areas like the Ward, Cabbagetown etc have long had their residents and later descendants leave).