AB, SK and ON all have support for the Catholic separate system written right in their founding legislation.  The fact that's the BNA Act for Ontario and the Alberta Act or Saskatchewan Act for the other provinces, is kind of immaterial. So, the fact this ruling happened in one of the three remaining provinces with constitutional backing for a separate system is telling.

It was always going to be harder in those three provinces, but was it going to be impossible?  Fast forward 100 years ... will we still have a Catholic system? We both know they won't exist, so the real question is: how quickly will they fade, and by what method will lawyers find a way around the constitutional restrictions.  It's going to happen, regardless.