One of the most shocking things about Star Wars: The Last Jedi was the fate of Supreme Leader Snoke, but, while he may be dead that doesn't mean he's gone for good. Fans are now wondering is Snoke might be making some sort of return for Star Wars: Episode IX, as Andy Serkis, the man behind the motion capture, recently had to cancel an appearance at a local comic-con. It's possible the reason for the cancelation was that he was needed on set for Star Wars.
The recent Keystone Comic-Con in Pennsylvania just happened, and among its litany of guests was supposed to be Andy Serkis. However, at the last minute, Serkis backed out. It's not uncommon for a few guests at one of these sorts of events to be forced to cancel, but there's usually a specific reason for it, and quite often it's production responsibilities.
There's precedent for a comic-con cancelation being due to Star Wars, even recently. Billy Dee Williams had to do the same thing not that long ago, leading many to speculate that Lando Calrissian would be making a return in Star Wars: Episode IX. That speculation turned out to be accurate so it could be here as well.
Of course, there are numerous ways we could see Snoke again. The most obvious would be as part of a flashback. While many were disappointed that Snoke died in Star Wars: The Last Jedi without revealing to the audience his origins or motives, the fact is that Snoke doesn't need to be alive to for the next movie to give us this information. Kylo Ren could easily talk about his own history and reveal a lot about where Snoke came from. If this happens we could see a younger Snoke build the First Order as part of events that took place prior to Star Wars: The Force Awakens.
There's also the possibility that we could see Snoke appear as a Force Ghost. We've never seen a Dark Side Force user do that, but maybe it's possible.
Finally, there's a third option, which is that Andy Serkis could actually be playing an entirely different character in Star Wars: Episode IX. The actor was almost certainly put under contract for all three parts of the trilogy, but since Snoke's death doesn't appear to have been specifically planned before Rian Johnson wrote it, this makes Serkis available to do something else in the new movie. If there's a character in the film that requires motion capture, and you have the best in the game available, why not use him?
Of course, all this assumes that it was even Star Wars that pulled Andy Serkis away. Perhaps he needed to do some last minute work on Mowgli, his directorial effort on a live-action Jungle Book. It really could be anything, but it could very well be Star Wars.