Making a whole movie just to retcon the parsec misuse in Ep IV was a choice
replyThey made a movie to make money. I doubt anyone holding the purse strings cared one iota if that bit were corrected or not. It’s not really a retcon either because they didn’t change anything.
replyThat had more or less been the explanation in the books for decades, and even in George Lucas' notes from 1977:
reply> It's a very simple ship, very economical ship, although the modifications he made to it are rather extensive – mostly to the navigation system to get through hyperspace in the shortest possible distance (parsecs).