The following was posted on D23:
In response to inquiries from Star Wars fan sites about Storm Troopers at the D23 Expo, D23 issues the following statement: "We were contacted by the Galactic Empire and have been advised that Imperial dignitaries will be attending Disney's D23 Expo," said Steven Clark, head of D23. "As a result, a legion of Storm Troopers from the 501st Battalion will be patrolling the Anaheim Convention Center on Saturday, September 12."
One of the speakers on September 12th will be Jay Rasulo, chairman of Walt Disney Parks and Resorts. Draw your own conclusions.