!greater_sudbury is actually the 2nd or 3rd oldest city-based community on lemmy.ca . It’s not very active, but should definitely be added to this list.
Also, !canadasoccer would be a good community to add to the soccer category.
For team-specific Canadian-based soccer teams, there’s !torontofc of the MLS (US-league with 3 Canadian-based teams). Other MLS sides include Vancouver Whitecaps and CF Montreal, which I don’t think have a community created.
None of the 8 Canadian Premier League teams, nor any of the numerous League1 Canada sides have taken steps to establish their communities yet (as far as I know).