Granted that the no-preassigned-seating is one of the reasons that WN's share of the business travel market will always have a certain "ceiling" (i.e., the share of business travelers who either don't care about what seat they get, or who can afford to go to the airport much earlier than they would if they had a preassigned seat).

However, adding preassigned seats, even for a portion of the aircraft, would add a lot of cost for WN. WN are doing fine with what they have now, they aren't going to mess with it by experimenting with preassigned seating.

And AA doesn't belong in the same sentence with US or UA... AA has not done nearly as much to alienate their frequent flyers as US have... and they are not on the verge of BK like UA.