I don't even think they were CTDs at that point. When they were coming out of UofM ( they were THE campus band at the time), they were Bad Brad Roberts and the St James Rhythm Pigs (one of the all time great band names) before changing to CTDs sometime around 1991 maybe?? Somewhere around there.
After them, in terms of that sort of Pop Rock world, it was The Weakerthans. There's been some others, but that genre of music has little to no financial success so most who are starting up now, go the "Country" route because it's slightly more profitable. Even CTDs member Murray Pulver joined Doc Walker to do the country thing for awhile before retiring from road life.
I think there's still a decent indie rock scene in the city, but I don't know a lot about that world. I know that Don Amero, David James, and the Petric brothers (Tom and Jay), have all had a lot of national success on the country charts. Desiree Dorion, Jade Turner, Sean Taylor, Kendra Kvemshagen (understandably, she just goes by Kendra Kay), and Quentin Blair have all been relatively successful regionally.
Personally, I'm a massive fan of Foster Martin Band, who have just recently reunited with lead singer and primary songwriter Ray Martin, and are booking gigs again. I haven't seen them live in nearly 20 years and I swear when I finally move home, one of the first things I do will be to check out their show.