Rian Johnson wrote TLJ based on the script for TFA. He had a script before we ever saw the film. And to make sure his script worked, he and JJ worked together to make tweaks. So Abrams knew where the story was going in TLJ before he committed to the final edit of the film. So many make it sound like TLJ was done in a vacuum without Abrams input and forget that Abrams was a producer on the film and I seriously don’t believe he did more that set things up in TFA (he was never supposed to continue the story). So whatever he might have envisioned he either shared with Rian or had no expectation that his vision would be followed. And we know that even though they publicly said they threw out George’s treatments that they used them. JJ and Rian have not shared how much of their story they borrowed from George’s treatment, but we do know that Luke in self exile and a female student came from George. How much more is anyone’s guess. But Abrams knew what lay ahead in TLJ before the premier of TFA. He even changed a few things in TFA so they fit better.