RLM is awesome.
Not only that but Kylo at the end tried to kill her again lol.
By ep IX, she will have already died.
We have to take into consideration that there was another hook for episode IX which is no longer true, and it's not Rian Johnson's fault.
Leia.
We know that Kylo Ren will predictably lose by the end of IX (unless they go crazy on that), but we're left asking ourselves how would the relationship with his mother be, and how would that affect the outcome of the story and give closure to the Skywalker family. Rian clearly set something for the next installment the moment he made Ren unable to press the button and kill her.
But now that the actress has died, chances are, we won't get something very compelling out of it.
Not only that but Kylo at the end tried to kill her again lol.
By ep IX, she will have already died.