It was nice to see Chewbacca in Revenge of the Sith, but it definitely was just putting him in there so the fans could go crazy.

When Chewbacca’s home planet Kashyyyk was attacked by the Trade Federation, he fights with Jedi Master Yoda, the troopers, and other Wookies to defend his world from the robotic minions.

He was also with Yoda when Emperor Palpatine initiated Order 66. Helping the Grand Master of the Jedi escape from the clone troopers trying to hunt him down.

But honestly what are the odds of Chewbacca running into Yoda? This is all long before he ran into Han Solo.