This is also related to the FRA-led Corridor ID Program (ID = "Identification and Development"), which has actually been able to distribute some money for studying new routes and implementing a bit of service. Corridor ID aggregated together a bunch of routes that had been studied by states and the feds, and has tried to put together a more unified vision of how to tie everything together, while this is specifically focused on the long-distance (>750 mile) routes -- I think the results of this are supposed to feed into Corridor ID, but I'm not totally sure.
Amtrak has historically never really had the authority or mandate to look into adding new routes on its own -- they've basically had to just respond to what states and the feds tell them to do. That's changed with recent legislation, which has allowed them to work on that "Amtrak Connects US" plan and work with the FRA on broader plans. That's about all I know, though -- the details of how Amtrak's plan, Corridor ID, and this long-distance study all fit together is vague to me, but at least we now have these two primary entities who are able to be points of contact working with all of the state and regional groups that have been advocating for things piecemeal over the past several decades.
Long-distance routes are federally-funded, while shorter ones have been required to be funded by states in recent years (after a 2008 law fully went into effect, I think?) -- something that might sound okay at first glance, but pretty silly when you consider how many states can fit within a 750-mile distance, and all the squabbling that they can do between them to torpedo doing effective work on shorter corridors.
Yeah, I'm definitely surprised by how many routes were suggested to go to the Twin Cities. Sounds like the group
All Aboard Northwest has claimed some credit for getting ones along the northern tier added. I kind of feel like the Phoenix – Twin Cities one in particular was done to create something that met the >750 mile requirement, since it kind of looks like 2 or 3 routes standing on top of each other in a trenchcoat.
Nonetheless, with the relative sparseness of population in the western US, a lot of these routes probably make the most sense staying long-distance and being federally-funded (assuming it ever gets off the ground), while a lot of shorter routes should mesh together in tighter webs in the eastern part of the country and other denser spots.