Ahh so SDQ wasn't added to the route recently as they claimed then. I can understand why it's required for this route, considering some of the rental car places ask for $4000 deposits. Just thought it was new for this route as the delta rep stated.
It will be the 3rd time I fly the route, and I almost purchased the biz class ticket as it was 814 versus 634 for the Comfort plus. But it's just a 4 hour flight I'll live in comfort plus.