As we all know, there are three levels of rail service - commuter rail, regional rain and national rail. HSR is a form of regional rail.
In the Maritimes, we are part of the national VIA Rail network, but just barely, with only 3x weekly service to Montreal from Halifax/Moncton. A service that sparse isn't really a "service" at all.
I think the time has come for commuter rail in central NS, connecting downtown Halifax to Windsor and perhaps as far as Truro on two different lines. Vehicular traffic in the city has reached a crisis point that bus service alone will not be able to solve. This is a municipal/provincial issue.
The main question is what to do with regional passenger rail? At present there is none (there used to be when I was a child). It would not be possible to rebuild a regional service to the levels that formerly existed half a century ago, but, I do think a single regional passenger rail service connecting Saint John/Moncton/Truro/Halifax on a single line perhaps 2x daily should be considered. There are about 1.25M people who would live close to this regional rail line. It would connect the three largest cities in the region and would provide an option to those people who prefer rail travel, or who do not have easy access to motor vehicles for travel. The bus service in the Maritimes remains suboptimal, and, there is
no air service connecting the larger cities in the Maritimes. This is an important distinction from the west where every city is connected by commuter passenger aircraft.
Just because denizens from larger Canadian cities feel that regional rail in the Maritimes is not worth the investment and that our relatively smaller populations don't deserve the service levels available elsewhere does not mean that Maritmers don't still have a need.
Canada exists outside of the Quebec City/Windsor corridor.