it said "Parking has a BGL jetway. Does that mean the jetway is static?
It means it has an animated jetway that use the standard .BGL format, controlled with the default CTRL+J command.
As explained on the GSX manual, it's not possible to detect a static jetway, since a static jetway doesn't basically exists, it's just a bunch of polygons. So, if a scenery has a fake/static jetway, GSX will say there's no jetway there.
Which is why, you CAN change that option. Which won't automatically create an animated jetway but, at least, it will inform GSX such parking has a jetway, so it would at least behave in the correct way, not sending a Bus and not creating front stairs.