I feel like we should be past the “Lucas’s treatments got dumped” discussion at this point. We know many of his ideas were the starting point for things in TFA (and TLJ to a lesser extent). The fact that they didn’t follow his treatments to the letter shouldn’t be a surprise to anyone.
It was certainly a surprise to George Lucas. Here’s Robert Iger himself recounting their first story meeting with George:
Early on, Kathy brought J.J. and Michael Arndt up to Northern California to meet with George at his ranch and talk about their ideas for the film. George immediately got upset as they began to describe the plot and it dawned on him that we weren’t using one of the stories he submitted during the negotiations.
The truth was, Kathy, J.J., Alan, and I had discussed the direction in which the saga should go, and we all agreed that it wasn’t what George had outlined. George knew we weren’t contractually bound to anything, but he thought that our buying the story treatments was a tacit promise that we’d follow them, and he was disappointed that his story was being discarded. I’d been so careful since our first conversation not to mislead him in any way, and I didn’t think I had now, but I could have handled it better. I should have prepared him for the meeting with J.J. and Michael and told him about our conversations, that we felt it was better to go in another direction. I could have talked through this with him and possibly avoided angering him by not surprising him. Now, in the first meeting with him about the future of Star Wars, George felt betrayed, and while this whole process would never have been easy for him, we’d gotten off to an unnecessarily rocky start.