Some people from the previous GSX has been in fact "retired", because their models started to feel old, we only left those which were of an higher quality, and they are in the minority. We'll expand a lot the number of different characters in the future.
We have multi-seasonal clothing for Marshallers but, in time, we can extend the feature to passengers as well. There's nothing special to code in GSX, it's only a matter of modeling and animating more and more models.