Rian Johnson is directing Star Wars: The Last Jedi which is coming out next week, and Colin Trevorrow was originally tapped to direct Star Wars: Episode IX.
While J.J. Abrams directed Star Wars: The Force Awakens and has remained on board the franchise as a producer.
However, in a move similar to what happened to Phil Lord and Chris Miller on Solo: A Star Wars Story, Trevorrow and Kathleen Kennedy were apparently having difficulty coming together on a vision for the film, and the director stepped aside.
The plan was to have different directors handle the other two entries in the franchise.