there is work being done to try to rebuild the scenery, yes...
there is work being done to try to allow for rebuilding portions of the scenery, yes...
there is work being done to try to allow for rebuilding portions of the scenery as certain aspects are updated, yes...
there is not anything that i'm aware of that allows just random editing/adding of airports and throwing them into the scene without rebuilding the scenery affected... this is because the scenery needs to have a hole cut into the mesh that matches the block of land that belongs to the airport and then the airport can be added during scenery generation...
there is also no guarantee that the work being done on the scenery regeneration capabilities will ever bear fruit other than being able to generate all of the world scenery in one huge multi-week long execution... we all sure hope it does but it is better to not hold one's breath while waiting

generating scenery is a massive and delicate project with the current tools...
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."