The trade reports that Reeves allegedly wants to utilize the Clown Prince of Crime as one of the multiple villains in the second and third films and plans to reference him in The Batman.
The story also mentions that he and Warner Bros. haven’t begun a casting search for the role just yet.
At this point, this should be taken with a grain of salt but, according to The Direct, Matt Reeves is planning to introduce a new version of the Joker into his trilogy.