It’s almost a guarantee, free marketing to Star Wars fans everywhere. What better way to market one film with another from the same universe. Marvel and Disney do it all the time, why not Lucasfilm, all which are owned by Disney.
I’m willing to make a bet on it, if it comes sooner than that, probably mid November or Thanksgiving time, but I have a feeling it will be with Star Wars The Last Jedi. It will be less than 6 months out, with no teaser of any kind, isn’t that a bit weird, if they didn’t release something by December? There is plenty of time to put together a 1 minute teaser of some kind and attach it to The Last Jedi. If you can’t, then that’s just ridiculous with everything they have shot already.