Well, I don't work there, but I'll try to share what's public and my hunches.
From the company factsheet:
"Southwest Airlines currently operates six reservations centers located in Albuquerque, Chicago, Houston, Oklahoma City, Phoenix, and San Antonio."
It's also a fact that they recently closed three reservations centers (in Dallas, Salt Lake City, and Little Rock). Agents at those centers were offered the opportunity to transfer to another center or a voluntary separation package if they chose not to move.
From the company's hiring page, it appears that there aren't any positions open for reservations agents.
