Until they started on AH III HTC had been updating 1 or 2 AH1 rides on pretty much every major update. Since then they have been concentrating on the art for the new terrain, creating the ground tiles, buildings, ships etc. Redoing an AH1 shape is almost as much work as a complete new ride, only the flight models and maybe the damage model carries over. Despite that we will get a new TBM on the next update. Once the new version is out I am sure they will begin getting the remaining AH1 stuff brought up to the latest standards as well.