also, i think what your missing is the whole concept of change for advancement or to move forward vs change for the sake of change.
was/is there anything wrong with the Yoda in ESB and Jedi? If you answer that truthfully its no, he was pretty darn realistic. Sure you can do things with a cgi version that you cant with a puppet, but they both have their pro's and con's. Cgi stands out especially when inserted into an 25+ year old movie. so would it look more life like? nope, probably not. even if it does, would the amount of work and time that has to go into the change be worth it. No, why not spend that time/money/resources removing matte lines, or getting the color level set properly instead of making changes that has nothing wrong with it.
in my opinion the worse possible justification for any change to the OT is so that it fits better with the PT. Its just backwards. The OT while chronologically takes place after the PT still came out first, so there is no reason that the 'facts' that it set up werent able to be followed. I would take the same thing if the PT came out before the OT then he went back to change the PT to fit the OT. How hard is it to make a story you wrote fit in with another story you wrote.
-Darth Simon