So some of the new event details were leaked via the App Store.
https://imgur.com/gallery/j2BBP9t
Event is Wreck-It-Ralph Breaks the Internet. Runs Nov 22-Dec 21. Characters we can see are Ralph, Vanellope and Fix-It Felix and Yesss. Mentions a Villain boss battle. Mentions new characters, attractions, decorations, like usual. BUT also mentions new princess costumes.
Event dates means my Windows game will get a pause in the middle, when I go to Japan. Hopefully, it will time out with the portion of the game where we all sit around for 3 days waiting for the next bit to open. But it will finish before we fly out for our Christmas trip the the in-laws. So I think I should be able to finish it all despite the traveling.