Will Amtrak ever be back to Wyoming? If so, how?
Unlikely. Here's why.
(1) The entire state of Wyoming has a smaller population than most metropolitan areas. It makes more sense financially for Amtrak to run a disconnected train from Columbus to Cincinnati than it does to run a train for the purpose of serving Wyoming.
(2) There is no political support for Amtrak from Wyoming's three politicians.
The only way Amtrak returns to Wyoming is if Wyoming is "on the way". Specifically if the current mountain route from Denver to Salt Lake becomes unusable. While it's also on the way from the Pacific NW to Denver, there isn't enough land traffic between those two areas to justify a train.
Frankly we're more likely to see service return to South Dakota, which has 50% more population than Wyoming, and that's pretty unlikely too.
I'm more interested in questions like "When will Amtrak return to Scranton?" The Scranton-Wilkes Barre-Hazelton metro area has a population about the same as the state of Wyoming.