Chanel, Dior, Gucci and more are betting big on creative reboots to reignite consumer demand amid the biggest luxury slump since 2008. But sticking the landing on an aesthetic refresh is easier said than done, and a new generation of creative directors faces the same systemic challenges that stymied predecessors. Fashion is midway through an unprecedented year of designer turnover: Givenchy, Tom Ford, Dries Van Noten, Dior (men’s), Celine and Margiela have already launched new creative visions.