If you looked at an Amtrak Timetable for the Maple Leaf right up until Covid......unless you read the footnotes.....Niagara Falls, St. Catharines, Grimsby, Aldershot, Oakville and Toronto are listed and look just like any other Amtrak stop in the schedule.
https://www.railpassengers.org/site/assets/files/20928/maple-leaf-schedule-031620.pdf
The former CN Station on the Maple Leaf route in Downtown Hamilton (pop 700,000) was closed and the stop moved to Aldershot years ago. But a big announcement is being made tomorrow and rumoured to be the start of all-day GO Train service between Hamilton West Harbour (old CN Station site) and Toronto. If the Maple Leaf does return....some mods would be required to the tracks at West Harbour to permit it to stop there