But in Europe there are different level of trains on the same route. Commuter, local, semi express and express.
VIA doesn't have that. You need to be able to take the local train that stops at all stops and transfer to a semi express or express train.
For example you need a local train making all stops which will take you from Port Hope and take you to Belleville or Kingston where you transfer to the express train to go to Ottawa or Montreal. Or take the GO from Eglinton to Oshawa and then transfer to the express train to Kingston where you can catch a local to Napanee. You could even have smaller stops like Brighton whici would be a good spot for a commuter train to take passengers to Belleville or Cobourg.
From the riders perspective, what difference does it make if the express train doesn't physically run in the same tracks as the semi express and local trains?
If a rider needs to take Toronto to Montreal, who cares if the express train takes a different route?
There WILL be express, semi-express, commuter and local on the same route. They will just be offered by two different lines.
The route that HFR/HSR will take in the North will really be pointless to stop at more than a couple stops as its quite empty up there. But the Lakeshore route to Montreal and the route to Ottawa will continue to operate semi-express and local/commuter services.
You can just look at HFR/HSR offering the express trains for that service, just on a different routing.
But there's no reason that it literally has to run on the same route.