I hope someone told VIA!
Also hoping the passengers all brought masks, as they'll be required to put them on at Niagara Falls. Since relaxing the vaccination requirements the Canadian government has upped the ante on onboard masking. Here is the latest from the website Flyertalk which, although specific to airplanes applies equally to trains:
This information can also be referenced on several government websites.
Amtrak's announcement is quite clear about masking requirements once across the border, as well as ArriveCAN and vaccination requirements.
www.amtrak.com
While ReserVIA did not show availability as soon as Amtrak did last week, VIA trains 97 and 98, the Maple Leaf showed up as bookable in viarail.ca over the weekend. Oddly, unlike before COVID, it is only bookable online to Canadian points, as far as Niagara Falls, ON on viarail.ca. It takes you to a page stating for travel from Canada to the US, you need to call. Before COVID you could book the whole route on viarail.ca, although booking through VIA did not offer Business Class. On Amtrak.com you can book the whole route (multiple segments 7097-64, 63-7098).
Amtrak announced it last week, Trains.com had it a couple days before the advisory was released on Amtrak.com, IIRC.