There does seem to be light at the end of the tunnel, but I fear it'll be another 6 months. A lot of the more reliable news sources (using Wikipedia's standards) are pinpointing a late 2020 to early 2021 estimate for a vaccine to get to general availability (with the later date being targeted for multiple versions). (
CNET's reporting) This, of course, centers around the US vaccines and not any foreign efforts.
Let me speculate, and I'll bring it back to Amtrak in a bit.
First, not everyone will go back to what they were doing. While I'd be heading back to the office, some are more productive out of the office. A good guestimate is 80% office.
Second, not everyone will be back immediately. It will be gradual, slowly ramping up over months as more people are vaccinated and company policies adapt.
Third, any tourist spot will also be slow to open back up. For the same reasons, basically. If it's not out and applied widely yet, why risk it? Disney isn't making money with it's resorts open at 50% capacity (with some exceptions on the "full shut down" side). Broadway shows are shut down until January 3rd. Anything major is ether shut down or a superspreader event.
With that in mind, Amtrak
laid out it's plans for LD cuts and restoration. In short, all LD but the AutoTrain is 3x/week October 1st through July, re-evaluating throughout the fiscal year, with the expected goal of resuming pre-pandemic service by August. All dependent on Congress... not doing anything.
Now given above... I'd say it's possible. I think one (or many) vaccine(s) will make it possible. The timing is what's critical there.