In the days ahead, the financial pages will convulse with excitement about China's reserve-currency milestone. On Saturday, Beijing's desire to unseat the dollar got a big boost as it formally secured the International Monetary Fund's good housekeeping seal.

But as the yuan enters the IMF's top-five currency basket, it's worrisome to see the man behind this breakthrough effectively sidelined. No, Zhou Xiaochuan, People's Bank of China governor for nearly 14 years, isn't losing his job. Nor has President Xi Jinping curtailed Zhou's travel or speaking schedule. Gone, though, is talk of the reform domino effect that internationalizing the yuan was supposed to unleash.

That, all along, was Zhou's grand design. The 68 year-old is a disciple of Zhu Rongji, China's most important change agent since Deng Xiaoping's market-opening campaign in the late 1970s. As premier from 1998 to 2003, Zhou's mentor increased transparency and accountability and tossed more than 40 million workers to the curb amid a huge state-owned enterprise purge. He was instrumental in China entering the World Trade Organization, which was a Trojan horse of sorts to ensure the nation would open up to a curious world.