If anything, many of these rural/exurb communities are already at the minimum population needed to support the industries that must exist outside of dense/expensive cities. These aren't the overpriced McMansions full of entitled upper class folks, those tend to be located near the city, and are quite healthy financially due to outsized local tax revenues.
I haven't really looked at Lafayette so it might count as rural but if the 3rd largest metro area of a state is the size ST says is unsustainable [2] then that bodes pretty poorly for all but 2 of it's metro areas.
I bet a lot of say New Jersey is close enough to either Philly or NYC to avoid being "3rd tier" but there's a whole lot of the country that isn't near a top-10 metro area.
[1]: https://en.wikipedia.org/wiki/Lafayette,_Louisiana
[2]: https://www.strongtowns.org/journal/2020/4/27/this-is-the-en...
For anyone that doesn't know what a "stroad" is, I hope you look into it. You'll never see the world the same again.