I imagine large urban areas will spring up around wherever a hyperloop endpoint is built. The builder might even be able to subsidize themselves by purchasing large radius of land around the endpoint prior to building it.
https://en.m.wikipedia.org/wiki/Shenzhen
http://www.newgeography.com/content/002862-the-evolving-urba...
It makes more economical sense to build a hyperloop between cities that already exist and can sustain it, than to think the world works like Transport Tycoon Deluxe.
Result: You can't create a truly vibrant city in an arbitrary location. You might be able to manage a bedroom community or suburb though.
An example like Shenzhen from a centrally-planned economy would tend to have limited applicability to the US, but this one is interesting because it's the exception that proves the rule. Shenzhen would've been an "important" place regardless, due to its being the first place in "mainland" China north of Hong Kong. Before 1980, the aforementioned central planning kept it from developing as fast as it probably would have otherwise. When they opened it for foreign investment, it took off like releasing a slingshot, hence the high growth rate.