From a June 20, 2014 story in The Hollywood Reporter:
"Contrary to reports that he will be directing the next two Star Wars film, Johnson will direct only Episode VIII, but he is writing a treatment for Episode IX."
From a Rian Johnson Twitter post dated April 24, 2017:
"That's old info, I haven't been involved in writing IX."
With Johnson out of the picture, “IX” director Colin Trevorrow is scripting “IX” in collaboration with Derek Connolly.
Connolly also co-scripted Trevorrow’s earlier directorial efforts “Safety Not Guaranteed” and “Jurassic World” and had a hand in the screenplay for “Kong: Skull Island.”
Before writing and directing Star Wars Episode VIII, titled "The Last Jedi" and due in cinemas Dec. 15, Johnson wrote and directed "Brick," "The Brothers Bloom" and "Looper."
Principal photography for “Episode IX” begins in July. It launches into cinemas May 24, 2019.
