When I was growing up in Southern California, “the Southland” was used in the same way to mean the Los Angeles area. I heard the term only in the mass media, never directly from a person in conversation.
A little googling turned up this list of media-only geographical terms:
https://www.cyburbia.org/forums/threads/nicknames-for-metrop...
I noticed this phenomenon when I moved to Chicago in 1978. I liked the city, but I thought that “Chicagoland” sounded stupid.