[UPDATE, Feb. 4: Sabre announced that AA’s Preferred and Main Cabin Extra Seat now are available in the Sabre global distribution system. A Sabre official said a “phased rollout” will wrap up in mid-February.] Sabre at U.S. points of sale on Feb. 2 will start facilitating American Airlines’ paid seats, according to a Sabre memo to agency subscribers. Those seats…