Ever since the new Star Wars trilogy was announced fans have wondered which of their favorite classic characters would return. Now, the voice of Yoda has spoken out about rumors that the Jedi master will be back in Star Wars: The Last Jedi. As one might expect, Frank Oz did not confirm that Yoda will be making an appearance. What's interesting, however, is that he also doesn't deny that Yoda will appear, and the lack of denial might say something in itself.
There's an unwritten rule when it comes dealing with rumors for major films that want to keep their secrets. If the rumor is false, the answer is "no." If the rumor is true, the answer is "I can't talk about it." Based on this idea, it would appear that Frank Oz's response to Variety about the rumors of Yoda showing up in Star Wars: The Last Jedi would appear to imply that Yoda may be seen at some point.
The first part of what Frank OZ says is certainly ambiguous. It sounds like Lucasfilm has specifically asked Oz not to say anything. While they certainly would have asked him to stay quiet after doing any work for them, the way Oz says it, sounds like Lucasfilm may have reached out to ask him to say nothing even if nothing is actually happening. However, his last part of the statement, that he'd be happy to talk about "it" once he can, certainly seems to state that there is, in fact, an "it" to talk about.
Of course, in this case, "it" could be many things. Maybe we'll hear Yoda, without actually seeing him, as we did with Obi-Wan Kenobi in Star Wars: The Force Awakens. Maybe Frank Oz is doing something unrelated to Yoda as a way to bring the performer back, something fans would certainly appreciate.
Still, one of the rumors that claimed Yoda would be in Star Wars: Episode VIII specifically said that the character would appear. It certainly isn't outside the realm of possibility. Yoda would be one of the easier characters to bring back. While the character has died we have the precedent of Force ghosts to fall back on, combined with the fact that since Frank Oz is still around, we can make the character still sound the same.
Whether or not Yoda actually appears probably isn't a piece of information we will have confirmed one way or another until the movie is released in December. Until then, we'll just have to parse everybody's comments to see what we can guess.