According to the Amtrak announcement, Dunkin’ Donuts Original Blend and Dunkin’ Decaf® Hot Coffees is available on the Acela as of April 19th. It will be served all day in first class and in the Cafe Acela. None of Dunkin Donuts' other products will be on the menu.
Presumably the Dunkin Donuts' coffees will replace the not so good coffee Amtrak has been offering on the Acela and its other trains. A personal opinion of course!
Amtrak plans to extend the Dunkin Donuts coffees to the Northeast Regional trains later this year.
The coffee will be brewed in the same equipment that Dunkin Donuts uses in its restaurants. Hopefully Amtrak's employees will be trained in how to properly use it.
If this works out it could be the first step in in-sourcing other food service expertise.
In 2016 the NEC accounted for 38.1 percent of Amtrak's passengers or 11.9 million ticketed riders. This seems like a pretty big market.