The article says the subjects were given similarly-shaped objects, not a sphere and a cube (as noted by comments on the article). This gives the impression that the question whether very rough differences in shape, e.g. sphere vs. cube, can be distinguished immediately after sight is restored is still unanswered.
I was going to say the same thing. I'd really like to see what objects exactly they used.
I have a variation on the original question. Suppose someone blind has never touched a cube. However, he knows that a cube is an object with 6 sides of equal dimensions and 8 corners. Then his blindness is suddenly cured. If he sees a cube would he be able to associate it with the description of a cube that's already in his head?
