It's been said that Frank Oz was spotted on the set of Star Wars: The Last Jedi, leading to Yoda Force Ghost speculation for the film.
Now while talking to Variety, Frank Oz is asked about Yoda in Star Wars: The Last Jedi where Frank Oz doesn't confirm or deny Yoda.
“I feel like I’m a prisoner at war here, and I can only give you my name, rank and serial number,” he said. “To be true to the people who asked me, and they are kind of my family, I have to say I’ve been asked not to talk about it. I love Yoda. I would be happy to talk to you about it at the time they let me.”
Yoda's voice was featured in Star Wars: The Force Awakens in the Rey Force dream sequence, and since Star Wars: The Last Jedi will feature Mark Hamill, it's not too much of a stretch that Yoda will make an appearance. Yoda appeared as a Force Ghost at the end of Star Wars: Return of the Jedi.
I wonder if there will be any other Force Ghosts in the movie? Obi-Wan?
Star Wars: The Last Jedi has a December 15, 2017 release written and directed by Rian Johnson starring Daisy Ridley, Adam Driver, Carrie Fisher, Mark Hamill, Domhnall Gleeson, Oscar Isaac and Benicio DelToro.
Star Wars: The Last Jedi is produced by Kathleen Kennedy and Ram Bergman and executive produced by J.J. Abrams, Jason McGatlin, and Tom Karnowski.