Lucky and his kind have not been permanently shelved, particularly with John Lassiter now calling the shots at WDI.
Lucky was a prototype. The ONLY existing model of his kind. It's not as if the prototype was kept in the shop and they made another one to walk around the parks.
There were few spare parts, no extra skins, etc., because he was only a prototype.
After a few weeks at Walt Disney World his skin was splitting in spots.
He was an extraordinary achievement and you will definitely see more free-standing Audio Animatronic figures in the future.