[millstone]

Wouldn't you consider the Born rule to be a testable prediction (though in an admittedly weak sense of simply being postulated)?

If the Born rule were found to be violated, it would invalidate Copenhagen but not MWI, which IMO means Copenhagen is more falsifiable.

[naasking]

> If the Born rule were found to be violated, it would invalidate Copenhagen but not MWI, which IMO means Copenhagen is more falsifiable.

All quantum mechanical interpretations depend upon the Born rule. A violation of the Born rule would rule them all out, except perhaps Bohmian mechanics which allows the possibility of non-equilibrium states, but we have no idea if those can be created.