Here's a paranoid theory: Perhaps Stephen Gardner will reintroduce "full service dining" on the Eastern trains for the purpose of damaging their financials.
We've already watched them slash service to three-a-week and cut consists until they were really short... resulting in constant sold-out trains at high prices. Well, if Gardner's goal is to destroy the long-distance trains, *that doesn't help him*. We can point to sold-out trains, high demand, high revenue, and demand longer consists and daily service so that Amtrak can realize more revenue.
What will he do next? He'll need to saddle the trains with some more costs in order to make them appear less profitable. Advocates are already breathing down Amtrak's neck about dishonest allocations of overhead costs, so he'd have to be pretty careful about pulling that sort of stuff again.
So... bring back a very staff-intensive dining car, but make sure it has as few seatings as possible, is supplied with insufficient food, and can't meet demand so that it will lose as much money as possible!
OK, I hope this isn't going to happen, but I wouldn't put it past them after the corrupt and dishonest shenanigans I've seen this year.