This is one of the stranger rumors that we’ve heard so far, but it actually kinda makes sense.
The rumor is based out of the program from a recent Japanese press tour attended by Daisy Ridley and Kathleen Kennedy. Attendees were given a press book that listed many of the cast, along with their character names. Warwick Davis was listed as Wicket The Ewok.
The easy way to explain all of this away is to say that his character is not named yet or is a secret so they just used his most famous Star Wars character name. Then there’s this other theory. A lot of the spoilers for the film have mentioned that The First Order (the new Empire) goes down to Endor to retrieve Vader’s mask… and slaughters the Ewoks in the process.
If that’s true and it is actually shown in the film (and not just mentioned in the text crawl at the beginning), this could mean that we see the demise of Wicket! Even better, it could mean that he survived and is part of the new Resistance.