I was told a lot of 4 day transcons. LAX-JFK,JFK-SEA, SEA-JFK, JFK-SEA... similar story for BOS, EWR, BWI, IAD, DCA, probably a sprinkle of LAX -SEA, and a DH or two. I don’t see any reasonable chance the 321 is based in SEA.
CLT was supposed to happen this summer, I was told announcement soon, thinking that might have just got pushed to next spring.