The official Limited Time Magic page has this to say about the event:
Get ready to go to Hollywood—the American Idol Live! Tour 2013 is heading to Central Florida. And for just one day, Limited Time Magic is giving you a chance to see your idols in person at Disney's Hollywood Studios! Join the fun on Wednesday, July 31, 2013 when a one-time-only American Idol celebrity motorcade—featuring some of your favorite American Idol Season 12 Finalists—parades down Hollywood Boulevard.