I could be wrong, but I think it's calling out those that live in the burbs and call their city home. Metairie as New Orleans, Montgomery County/NOVA as DC, etc.
I mean, I tell people not from the areas that I was raised in New Orleans and I live in Baltimore, but it's been burbs. My postal addresses in Birmingham were all Birmingham so that one would probably be acceptable to the Chicago Urbanist - not that I give a flying...