I think that most people on this forum would agree that in a perfect world, a restoration of rail passenger service to Montreal via Vermont would be a nice thing. The problem is that this is not a perfect world. Unless the states and/or Canadian sources step up to pay for it, it simply isn't going to happen. Amtrak currently can't afford to provide service on a lot of routes connecting much bigger markets within the US. It's not about to increase service to Canada in the current funding environment.
Regarding potential state support for a service restoration, it was Vermont's budget issues that led the Montrealer to be cut back to St. Albans, and Vermont hasn't suddenly become wealthier. Massachusetts is totally tapped out regarding transportation funding these days and New Hampshire's financial support for rail passenger service has historically been minimal. And as others have noted, the former B&M Northern Division between Concord and Lebanon has been abandoned for over twenty years. It ain't comin' back anytime soon.