How do you know the 4k restoration was abandoned? We had official press about the cancellation of the 3D release, but nothing official that the 3D would be based on a new scan or that this scan was for the 3D.
I have no idea if they were abandoned or not, obviously.
But weren’t they being worked on pretty close to the time of the Disney purchase? It’s possible that they wanted to do it themselves or with another team, or were in some way unhappy with some aspect of the restoration project.