I think that Lucas (and Christensen as his actor) wanted to indicate by that change that pedophelia was common among Jedi and among Sith lords. That’s the only reason I watch the special editions: to get that naughty pedophelia hints. So we all feel guilty and guilt is the way to the dark side.
I think that the main reason for deleting Shaw from those scenes was his refusal to hint at any pedophelia in Star Wars. Strong pedophelia was always the main creative force behind Lucas, but in the early 80s the tech was not available to show that on the big screen.
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