Yes, coordination between apps would be the hard part and I see no evidence that it exists. There is a lot of writing in English that does not point to anything canonical from China. It does not make clear exactly what obligations are placed on app developers. I remain skeptical that coordination between applications is happening.

I would love to see any evidence of this. It should be easy if it exists as there would be documentation telling app developers how to use the central database. I would imagine an ecosystem of libraries would exist to make it easier for app developers to satisfy these obligations.