As I understand it, one of the biggest and constant tasks of the Communist Party of China (CPC) is ensuring the various preexisting and long standing systemic forces within China that would otherwise pull the country apart don't. Ethnicity, regionalism, and so on. This, much like Tito and his regime achieved in Yugoslavia. Note how quickly that country came apart once Tito ceased to be.
If the CPC lost its ability to function nationally toward that requirement then the country could pretty quickly revert back to its regionalism / warlord type set up. This, made all the worse with numerous second tier former CPC members all declaring themselves to be THE true leader of the CPC. Say, Mao dies even more suddenly or was assassinated. Or that his successor loses his attempt to firmly gather all those reins of power in hand.
This is one of the things which keeps the leadership of the CPC awake at night and why they're so adamant in maintaining such systemic control over China as a whole even today.