That's an API someone has to write, and Google just burned down Analytics for no particular reason. It won't happen. The UTM parameters were a Schelling point.

That's an API someone has to write, and Google just burned down Analytics for no particular reason. It won't happen. The UTM parameters were a Schelling point. They won't be replaced because once you try to coordinate something else, Apple will block that too, so no one is going to bother trying. Google will be happy to just keep the data to themselves instead of sharing with others.