It's been made very clear that the Blu-Ray and DVD release of Star Wars: The Force Awakens won't contain any extended scenes, only deleted scenes. The first cut of The Force Awakens was around three hours long. The theatrical release of the film came in at two hours and 16 minutes, so we missed out on nearly 45 minutes of footage.
We may never find out what the extended scenes contained, but the new book called 'Star Wars: Rey's Story' (noted by Making Star Wars), might give us an idea.
During Rey's 'Force-back' (flash back) sequence in Maz's Castle, in The Force Awakens, the scene could have gone on to detail Darth Vader fighting Like Skywalker.
On page 99 to 100 of the book details the missing sequence:
"As she peered into the distance, she saw a man in black wielding a red Lightsaber. His face was covered with a mask, molded to approximate a human face. But the mask’s eyes were dead and empty. The man’s red Lightsaber clashed against a brilliant beam of blue. A young man with blond hair raised his own Lightsaber and fought furiously against the monster in black."
The book goes on to depict a war-like flash back sequence:
"Before she knew it, more images flashed through her mind: a hero stabbed by a fiery blade, a battlefield filled with soldiers, a blue and- white droid beside a lost Jedi."
Whether or not these scenes were initially included in the film, we will never know. Luke Skywalker only appeared in the film very briefly at the end, as Rey approached him on a secluded island, offering him the lightsaber.
