Actually, this isn't true. The whole "9 film saga," stems from an old interview with George Lucas, in which he was asked if he ever intended to make a further trilogy. He answered yes and was then asked if he intended to make eps 1, 2 and 3. Again, he answered yes.
This was construed by many to mean that he intended to make eps 7, 8 and 9, as well as 1, 2 and 3, when in fact, Lucas was only ever referring to the prequals when he answered both questions.
1-6 was his entire intention by the time he'd finished Return of the Jedi. That film completed his story. Of course, initially, he only ever intended one film. If you've ever read his early synopses for SW before it finally came out, you'd know there was never any intention of any sequals or prequals. Heck, in the original story, Princess Leia turns out to be a God-like alien creature, kinda like the Q out of Star Trek, who enRAB the whole Rebel/Imperial conflict with her sheer, unstoppable power. God, I'm glad that version never got made!