IIRC, they were only shown at Celebration. A couple other shots were slightly altered, like a view of the Trade Federation ships over Naboo.
The OT has yet to be screened, if their conversions were finished at all. Some of the changes seen on Blu-Ray, (like all the new gizmos popping out of Artoo when he’s shot in ROTJ) were apparently to enhance the 3D effect.