These are canned animations tailored for a specific scenery/airplane/parking position. Doing the animations is not difficult, at all. What's difficult, is making them generic and aware of the airport.
Look for example at our wingwalker: he can follow the airplane and the truck doing the pushback, regardless of the airport used or the pushback path.
We'll surely use GSX technology to enhance sceneries even more in the future, but the main issue right now, is that we don't have much headroom because of the rest of memory-hungry products that people use, which severely limits the available memory at our disposal.
See what happened with CYVR, a scenery which is probably our best yet, that has been unfairly bashed because many users were already close to the OOM limit in that area and mistakenly labeled CYVR as being the cause of their OOM, just because it was the last thing they installed.