There will be no footage, behind the scenes, or trailer at D23 according to J.J. Abrams:
“It is true, we are showing no footage, behind the scenes or otherwise,” director J.J. Abrams tells EW. “In the fall, there’ll be a trailer.”
So what could possibly be in store for that panel? It only happens every two years, you would think there would be something huge coming. Maybe Star Wars Anthology: Rogue One will make the huge reveals at that panel for Star Wars? Only a few days to go!