Sorry for confusion on my post. I'm a travel agent and work on the Sabre platform and this is cut & paste from Sabre availability:

05MAY FRI SEA/PDT STS/PDT‡0
1AS/** 2475 F0 D0 P0 U0 A0*SEASTS 100 355P 605P DH4 0 DC /E
Y7 Z7 S7 B7 M7 H7 Q7 L7 V7

Please note First Class is 0 availability.

Seat maps do NOT show a First Class cabin, which leaves me confused. I speculate that AS may add First Class OR plan on offering equipment that offers First Class.