BA's RM software runs locations by IATA code through an algorithm and publishes from there if it is worthwhile. No human being is considering filing or not filing.

In OP's case, there is economic downside to BA. With limited onward service to a very small location (OP may be the only person who benefits), BA puts itself on the hook for EC 261/2004 compensation when it is delayed into SEA causing a misconnect onward.