The Livestream announcing the upcoming Indiana Jones mini event just concluded. Marion and Henry Jones, Sr., were mentioned as part of the Season Pass content. I think most of us already knew that. If you purchased the Kingdom Pass, you probably already have Henry Sr. Marion is the reward at Level 150, so she won't really be able to help with the mini event unless you really want to use gems and $ to get her that quickly. I am just about at level 58. There is no way I could get to 150 by September 1st, when the mini event ends.
Prior to the mini event, there will be a cascading tapper event from August 10th - 16th. The final reward will be Isabella from Encanto.
For the mini event, there are going to be 3 characters. You have Sallah, Rene Belloq (Premium) and Indiana Jones. Looks like only a single new attraction as part of the mini event. There is another attraction as part of the Season/Kingdom pass (not sure if only with Kingdom).