Im. Reply to the OP, i don't think that China is working on it within the past 6 years in my opinion.
Given the crypto scene began to grow earlier in the decade and also the country here is China, it could possibly be a case of a team studying crypto over the years and giving the government inputs on how they could use it. A big factor here would be the currency getting tied up with the social credit system in China which is known to involve every citizen of the country and again, a leverage to monitor the entirety of the nation's (partial?) economy.