The airport is the second-most driven-to location in any GTA after your own house. Vice City's airport has appeared in aerial frames in Trailer 2 - fleetingly, but visibly.
The bigger picture is covered on the airport system page.
What the aerial frames show
A multi-runway mainland airport, located north-west of Vice City proper. Big terminal building facade. Parked aircraft on aprons. Nearby service infrastructure - hangars, fuel.
The real Miami International is in approximately the same relative location to downtown Miami. The layout you see in the trailer aerial shots is consistent with that arrangement.
What it's likely to be used for
Acquiring aircraft - GTA's airports have historically been the easiest place to find a plane to steal. Story missions centred on cargo, smuggling or escape. Possibly a starting hangar as part of a property system, GTA Online-style.
Heist-side: airports have been popular spots for heists throughout GTA history. There will likely be at least one mission at the Vice City airport.