There used to be a lot of music-based subcultures in the 80/90's such as "Goths", "Mods", "Ravers", "Rockers", "Housers", "Skaters" and "Preps" etc. that were perhaps not entirely Toronto-based but they were easily recognizable by seeing them together in school or on the street. When Hip-Hop was emerging, there was a more distinct clothing style and culture but nowadays, kids who are into Hip-Hop look very similar to those who like Pop music.
Maybe I'm old and out of the loop, but I don't really see any unique clothing styles, subcultures or similar groups in Toronto. I think a few years ago, the "Hipster" look was big but it wasn't tied to any big music movement or any specific styles or brands. It was just being "quirky" or "weird" for the sake of it.
I feel that fashion and style are being homogenized and most millennials look basically the same whatever music or thing they are into. When I walk through some big chain shops popular with young people, the clothing looks all the same whatever the store.
But hey, if you know what the big subcultures and styles are with the kids in Toronto these days, please let me know