Why would it want to ? They're export-driven : becoming a reserve currency is not in their interest. The RMB would appreciate and hurt their competitiveness. Plus, they wouldn't be able to control/drive its value down once it has spread over their border. They paradoxically need to be mostly self-reliant and therefore grow their consumer-base before that happen otherwise they're just putting their fingers in the cogs.
China upstart phase when they viewed themselves as purely export-driven to shore up their economy is over. They now think of themselves as a global power with an internal market deep enough to sustain their own growth and deep tie with countries in Africa and South East Asia with which they would rather do business in their own currency as a way to shore up their depencies towards them.
You are confusing current China with China a decade ago.
