Yeah, VIA's kind of gone the same direction as Amtrak, except their generated schedules are even harder to find. Amtrak's are at least under "Schedules" while VIA's are under "Arrivals and Departures" then you have to scroll down the page to "Accessible Timetables"
The RPA's are easier both to get at and to read.
In any case, the Canadian is still twice a week and will likely remain so year round indefinitely. The third train between Vancouver and Edmonton (3/4) that ran summer 2019 will not be returning. It leaves Vancouver Mondays and Fridays at 3:00 pm and Toronto Wednesdays and Sundays at 9:55 am.