ANAHEIM, Calif.— Bob Iger looks down at his phone and frowns. “Why is the stock market dropping?” he murmurs to himself, sitting in the back of a BMW ferrying him around Disneyland during last month’s convention of superfans, where he is showing off the new Disney+ streaming service. I know I have to give him the bad news. “You are hereby ordered,” I tell him, “to immediately start looking for an