The media reports about the german version of this include getting a one-time code from the health authorities that you have to enter into the app to mark yourself as infected.

As far as I understand, the proposal from Google and Apple is about the underlying framework, but you can set up additional controls a level above in the app and the server infrastructure. So it's likely by design that it doesn't address the issue as the solutions to ensuring only verified cases can trigger alerts must be specific to the local circumstances.