FEW FACES IN BUSINESS are more familiar than that of longtime Starbucks leader Howard Schultz. But the recent announcement that Schultz would return to the coffee giant for a third stint as CEO left corporate strategists baffled.

Outgoing CEO Kevin Johnson informed the board last year of his intent to retire. Still, chairwoman Mellody Hobson acknowledged in a CNBC interview that the choice of Schultz as interim chief “was recent.” A permanent replacement, she said, would be named by fall.

Coming from a company of Starbucks’ size—it brought in $29 billion in revenue in fiscal 2021—such improvisation pointed to a breakdown in succession planning. “Starbucks’ board presumably had a year to find Johnson’s successor, and they weren’t able to find the right person,” says Pat Petitti, CEO of consulting firm Catalant. (Starbucks declined to discuss the transition with Fortune.)

To be sure, Starbucks needs a leader with serious operational chops. The pay will be attractive: Johnson’s overall compensation reached $20.43 million in 2021. But Starbucks has a dauntingly ambitious plan to reach 55,000 stores globally by 2030, up from around 30,000 today. And its share price has fallen almost a third from its 2021 peak, though it rebounded a bit after Schultz’s return was announced.

Perhaps the biggest challenge the new CEO will contend with is a growing unionization drive and shareholder dissatisfaction with how the company has addressed it. Nearly 140 stores across 26 states have filed to hold elections on whether to unionize, and Starbucks has been criticized for heavy-handed tactics in opposing the organizers. As CEOs scramble to satisfy a wider range of stakeholders than ever, the labor conflict has become a lens through which the world judges the company.

That conflict may help explain the comeback. Schultz is widely credited with building Starbucks’ reputation as a good place to work—a reputation that influences investors, customers, and potential employees. As executive chairman, he has been involved in the company’s efforts to persuade workers not to unionize. But the billionaire exec seems to have retained a wide base of support in the rank and file—and whoever follows him may need the same.

“At a moment when the next generation of consumers has a strong desire to support corporations where workers are respected, the board needs to decide if the company can afford to antagonize its workers, or if it will meet the moment,” says Dieter Waizenegger, executive director of SOC Investment Group, a Starbucks shareholder.

The last time he was CEO, Schultz guided Starbucks out of the Great Recession. He and his successor may now face an even tougher climate.