DominicCobb said:
I would argue that Luke and Leia being revealed as siblings in ROTS is much better, dramatically speaking, than having the reveal be in ROTJ, for a couple reasons.
1. What is a better reveal, Obi Wan plainly saying "you have a sister," and then Luke correctly guessing Leia; or Luke being born, and then all of a sudden, twins! Luke has a sibling?!? Padme names is Leia! Luke and Leia are siblings! It just seems more exciting to learn it this way.
2. It would be a nice payoff for the machete ordering, connecting ROTS and ROTJ further and making the whole flashback worth while, as you get new information about the characters you started with.
I never though of it that way, and now that you mention it, that actually would be much better. So then it certainly makes sense to do machette ordering, plus it would give a nice semi-cliffhangar to ROTS. Thanks for mentioning that.