The 2nd reason that he does this, is so they can save a little production money and reuse those shots already created for Episode I. They saved a few thousand by doing this.
Has this been confirmed? Is it even possible to reuse/transfer CG files from the late 90’s on to modern systems? Though I suppose Beggars Canyon was a miniature, so maybe they just had to find the original film negatives for those shots. Though IIRC the rocky desert landscape was mostly CG.
The Phantom Menace was shot on 35mm, the other two Episodes were shot digitally. All they did was remove the pod racers, they did create a few new shots for it, but mostly used the 24 year old footage.