Regarding WestJet in Montreal... WestJet's network is still mostly in Western Canada. With that said, since C3/Royal/CanJet/Rootsair have all perished, the Eastern Canada market is very much all AC's. However, it takes time to negotiate for slots, terminal space, hire/assign new employees in a new city, acquire aircraft to run a new route, etc, etc, so it will take some time to add new destinations to their network. I am sure WestJet has an extensive list of new cities they want to add to (Toronto, Montreal, Halifax, St. John's, US cities, etc, etc) but they are growing at a controlled rate. So if things go well, maybe in a year or two you'll see WestJet Montreal service.
Like the article said, WestJet does not even have aircraft available to fly to YYZ till this summer... so it'll be a while after that before Montreal is added.