Square Enix was recently asked about whether there would be a chance to see Star Wars and Avengers characters in Kingdom Hearts III. The answer was… not likely. [Thanks, Mobile01!]
According to Kingdom Hearts III director Tetsuya Nomura, chances of the two properties appearing is very low, despite being all under the Disney umbrella. The reason is because the characters in these two movies aren’t Disney-original, even if the property is now owned by them. Getting them into Kingdom Hearts would thus be very difficult.
Kingdom Hearts III releases in Japan and Asia on January 25, 2019 and in North America and Europe in January 29, 2019 for PlayStation 4 and Xbox One.