I doubt it would make much of a difference. Children growing up in rural communities typically move to a bigger city as soon as they can, which is where they then find mates and start their own families. I suspect not many young people are going to give up the social opportunities to stay in a small town or move back there.

But when they want the family, they have the option to go someplace to build it. That's the point. Right now the people meet in the city and stay in the city because they're tethered there.