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.