Originally Posted by SEA_Tigger
Unlikely, I imagine. They tend to favor increased frequencies to handle capacity, so a two-class 787 with 300 seats would probably not fit well into their system. While the transcons are a bit "thin", the 737-900X would be the better plane (since capacity will be right there with a 757-200 without the issues of flying a seperate plane type) if they want to keep frequencies low and increase capacity a bit.
The 787 might be a really good fit for AS, particularly if they ever go after routes from SEA to NRT or LGW. It could also work for them on routes to BOS/EWR/IAD. The 787 is going to offer significantly lower operating costs, perhaps so much that the cost of operating a -900X and a 787 on a transcon route could be rather similar.