The plot leaks that were being posted throughout the months leading to the release were very detailed, and proved to be astonishingly accurate. Those leaks contained some scene descriptions that weren't in the theatrical cut. Since the rest were so spot-on, I think it's a safe bet that those scenes were indeed filmed and cut. You might end up getting some of those in deleted scenes on the blu-ray. Here's a list of some that I took note of:
- The opening scene with Kylo on Mustafar was much longer. The Oracle (spider thing) reads Kylo's mind and taunts him about his feelings for Rey. It also warns him that his path will soon lead to his end, but then gives Kylo the wayfinder. Hux and Pryde were also there on Mustafar where Kylo and his FO troops were rampaging through the woods for an extended bit.
- The next sequence with the Falcon being chased by TIEs was more involved, and included more shots of various aliens onboard working with Poe and Finn. The big yellow slug alien had a larger role, for example.
- When Kylo first reaches Exogol, his conversation with Palpatine had a lot more to it. Palpatine confirmed having survived DS2, and was shown being tended to by the Sith loyalists. Palps actually describes to Kylo that he went to the Unknown Regions (where Exogol is) following the battle of Endor. He's also the one who tells Kylo about the Dyad, and how he wants Rey and Kylo to both inherit his throne.
- On Pasana, Lando tells them that he had a daughter who was stolen by the First Order. That was why he never left there with Luke.
- Luke was supposed to be at the Resistance base with Leia when she died (at least his voice was). He was there to pass on one final lesson to her (I'm not sure if that means the Force ghost knowledge, or something else).
- In one version of the climax, Palpatine supposedly used a lightsaber when battling Kylo and Rey.
As an additional note, the movie was originally described as opening with the flashback scene of Luke and Leia sparring/training. This was supposed to transition to Leia helping train Rey. My guess is that there had to be additional exposition (not voiced over by Luke) for that to make sense.
