What I think Iger needs to accomplish are a few things.
Right the ship of state at Disney. Undo some of the more pernicious and enraging aspects of Chapek's work. Ousting Kareem Daniels and his lieutenants and handing control of greenlight and distribution back to their studio divisions was a good decision.
After that, what could be next? Absolutely Iger needs to get the streaming business in the black. Media divisions like ABC and ESPN also should be more seriously addressed, whether that's from fixing those assets or spinning them off.
As for the parks...I think that Iger recognizes that they need some adjusting as well. The most immediate and popular decisions he can make include getting rid of the reservation system as well as allowing park hopping all day once more. I also hope that Iger makes fixing Genie+ a priority. If Disney is unwilling to go back to FastPass, then they could at least do some things to make Genie+ more attractive. Namely, they could give guests one free Lightning lane per day at the park and make the app more consumer friendly. I really like Universal's Express Pass system. Maybe offer something similar with Genie+?
I also think that Iger should look to Epic Universe and see that Disney needs a response in Florida, just like Tokyo Disneyland recognized that it required a response to Super Nintendo World and Studio Ghibli. What that response entails, I don't know. But the company cannot allow itself to be caught flatfooted again by Universal.
Also, I sincerely hope Iger invests in the parks more with increased maintenance, better conditions for cast members, and quality of life improvements to existing attractions to make the guest experience more satisfactory.
Perhaps the most crucial thing that Iger must accomplish is finding a successor and actually preparing that person for the job. Whether it's someone from within the company or an outsider, Bob Iger must get succession right this time so the company isn't stuck with yet another Disney succession crisis. I think people will forgive Iger if he can get this right, Chapek will just be remembered as an unfortunate mismatch. But if he botches succession a second time, Iger's legacy might be less rosy than he wants it to be. There is no perfect choice for the CEO position. But perhaps Disney should know post-Chapek what it doesn't need. Namely, someone who doesn't understand the importance of maintaining a friendly relationship with both the entertainment community as well as the business community. I hope Iger's successor is someone who becomes apparent in the next few months, as this person must begin the process of training right away.
For all of Iger's positives and negatives, there can be no doubt that he was a visionary who changed the company profoundly in the same way that Eisner and Walt did before him. Let's hope he can get the company's mojo back and find someone who will lead the company into the future.