Kingdom of the Planet of the Apes has proven that War for the Planet of the Apes may not be the last time that Caesar is seen alive, with the film setting up a strange way to bring him back in the sequel. Caesar was the main character in the modern Planet of the Apes trilogy, but due to his death in the third film as well as the 300-year time jump, he isn’t seen alive in the newest movie. However, Kingdom of the Planet of the Apes 2 may be able to bring Caesar back.
https://screenrant.com/kingdom-planet-of-the-apes-2-caesar-return-time-travel-setup/