One of the interesting things about this is that, from my perspective, VistA's sort of a mesh of servers rather than the hierarchy we might expect from a federal system. Perhaps that's because of the complex interplay between federal and state and local laws. But anyway, there's probably a "station" for VistA near you that serves your area, and that's very similar (though not identical) to the "station" in the next neighboring area/metropolis/state/whatever.

But weirdly it seemed like the plan to roll this out was to replace all of the functionality at a given VistA station, rather than to do a strangler fig sort of thing and work on supplanting VistA's functionality in a specific functional area (whether locally or nationally). I don't know if that's because of the aforementioned complexity of laws, or the complexity of how the system(s) is/are administered, or other reasons that would elude me.

It's, uh, it's a fun situation.