(Bloomberg Businessweek) -- Long before he became chief executive officer of Walt Disney Co. in 2005, Robert Iger developed a habit of waking up on weekdays at 4:15 a.m. and working out. Lately he’s been getting up around that hour on weekends, too, to exercise and watch early versions of his studios’ movies and television shows. He’s been obsessing over the first season of The Mandalorian, a space western from the Star Wars univers...