As an outsider, looking at the list of bands I'm not really picking up any strong threads - it's a diverse list. So my guess is that there wasn't a signature Canadian sound in the 70s, except that the scene was eclectic.
Not being competitive but just as an observation, I think Aussie pub rock in the 70s had more of an identifiable thread than Canadian rock (but I might just too close to be objective).
To me 70s Oz rock was marked by big fat money beats with lots of 4 on the floor - ACDC, Midnight Oil, Cold Chisel, INXS, Jo Jo Zep and the Falcons, The Angels, Rose Tattoo, Jimmy and the Boys, The Radiators, etc. I was always very conscious of it because I preferred trying to to flow rather than slamming on the drums and it meant my style didn't quite fit in.