The M&L Branch will never see a train again but for the sake of discussion, if it were brought back Londonderry/Exit 5 (Wilson), would likely be the terminus with connecting shuttle busses to and from there and the airport if needed. Staying in the corridor and tunneling under the airport or rerouting the ROW around the airport, will be too costly. Forget about freight, there is nothing big enough to support the operations.
It takes real skill to choke on air, fall up the stairs and trip over nothing. I have those skills.