About the update we're getting tomorrow, I've given it some thought and I think it's going to be something akin to the Master of Masters talking (or maybe even actually being revealed) and explaining how he planned everything and pulled the strings to get the X-Blade; and now, after much time, he's on the cusp of achieving his goal--then flash to something happening in the future with Sora and the Seven Lights (or maybe the new stuff coming with Player, Ephemer, Skuld, and/or Chirithy) and then "Reconnect Kingdom Hearts" or "Unchained Season 2" appears on the screen.
I just think it'll be something like this, similar to Master Xehanort's "This was all my doing" scene in DDD, and also kind of like the secret ending added to the Re:Coded cinematic that deals with something touching simultaneously on both the past and future.
IDK. What do you guys think? Place your bets now. LOL.