We can start talking about "revealed preferences" once it's very cheap to move out of the city and to the country, and when it's equivalently cheap to move into a city. As long as big cities are absurdly expensive to live in and have all the good jobs, I'd say it's mostly path dependence at play.

(Also, as someone who moved to a small town, married and has a kid, I desperately want to get back to a large city - small towns are depressing and soul-suckingly boring.)