Alaska likes to keep a young fleet and they're trying to aggressively expand. They haven't announced plans yet for the Airbuses but even if they were going to get rid of them it would take a while. There just aren't enough 737's out there to be snatched up and there isn't any room in Boeing's production output for a large order to be made for quick delivery.

Plus, they're still getting a couple more Airbuses delivered.