A brief gameplay was also posted on YouTube, but it has since been removed. According to Eurogamer, it served as a warning to fans to do their best to avoid leaking any possible spoilers.
The full version (!) of KH3 appears to be out in the wild (some screenshots and videos exist that I won’t share here) But yeah, be careful on both social media and YouTube pic.twitter.com/6QKhu31IaZ — Nibel (@Nibellion) December 15, 2018 Responding to the leak, director Tetsuya Nomura says the biggest spoilers are not yet in the game. He says that the ending of the game, specifically the epilogue and secret movie, will be released at a later date.
— KINGDOM HEARTS (@KINGDOMHEARTS) December 16, 2018 In light of the current development, this can be seen by fans as a good thing. And indeed it is a smart move, particularly if it’s to be released as day-one free DLC. Because obviously it’s a bad idea to lock the ending of a game behind a paywall. (Source: Eurogamer)