Québec has developed his fair share of defenders, some have hit bumps on the road, but there is a good list of up-and-comers on defense. Off the top of my head:
Thomas Chabot, Samuel Girard, Samuel Morin, P-O Joseph, Guillaume Brisebois, Jérémy Lauzon, Zachary Lauzon, Nicolas Beaudin, Philippe Myers (I'll grant you he's from NB), Jérémy Roy (if he can catch a break injury wise), Thomas Grégoire, Samuel Bolduc.
There is for sure work to be done in terms of development, but you would have bad fate to say Québec hasn't developed a defender recently. 3 out of those already are in the NHL and a couple are on the cusp (Morin, Brisebois, Roy, J. Lauzon), while the others are quite promising.