If hypothetically the OT gets proper 4K transfers of in their unaltered forms, could the Revisited Trilogy look and sound just about the same?
You ask very silly questions sometimes.
An official 4k Blu-Ray of the unaltered theatrical cut, perhaps a scan of a 77 Technicolour print, probably an interpositive if anything, would look nothing like an unofficial fanedit, made to be what the Special Editions could of been, coloured and crafted too look like what a fan wanted to create. From the custom sound mix, to the new visual effects.
Revisited is not a theatrical preservation, never has been, and has never aimed to be anything like the unaltered original cut.
It’s like asking if Revisited is going to be anything like Harmy’s 3.0. Completely different things with different goals. They would never ever look or sound exactly the same.