After coming across a rumor that Yoda will be appearing in Episode VIII, I talked to General Flux to see if there was any truth in the matter. To my surprise, this turned out to be correct. Yoda will be in Episode VIII, sharing a scene with Luke and Rey during a meditation session which I mentioned in one of my earlier posts. This meditation ends when Rey is shaken by the vision of The Knights of Ren.
A puppet version of Yoda, like what was used in the original trilogy, will be used in Episode VIII but from what Flux had heard about it, there will be some CGI added to make Yoda look less puppet-like in his facial movements and to appear as a Force spirit to Luke and his new protégé. Flux went on to tell me that Obi-Wan appears in the scene as well but not physically. A stand in read his lines while on set but Flux believes Ewan McGregor from the prequel films will do voice overs as he did in The Force Awakens. Flux wasn’t sure why Obi-Wan wasn’t physically there like Yoda is, so I will speculate.
In an EU novel, Heir to the Empire by Timothy Zahn to be exact, Obi-Wan tells Luke via a Force dream/vision that he is unable to appear in physical form because he must move on to the after life. Perhaps this same situation happens in the new canon but since Yoda is more powerful than Obi-Wan with the Force, he is able to hang around longer. Or because it would be confusing due to the fact that Sir Alec Guinness portrayed the character in the original trilogy. Guinness could be recreated with CGI but both Flux and myself find that unlikely.