Although the track configuration for the Septa + CSX PTC segregation in the past couple of years works in favor of a track expansion, the capital expenses would be quite large to bypass the neighborhood and arrive at the passenger terminal on the West side of the airport.
In addition to the taxi's that frequent the station, a shuttle bus would be quite easy to setup if it met the septa departures & fit Frontier's schedule. With a
proposed terminal expansion, and a temporary shrinkage of cheap $8/day parking, it would be the optimal time to start such a service.