True, you don't even need the notice. But the point remains that if that's all you are putting then legally CPAN is infringing on your copyright when it mirrors your modules. (Note: I am not a lawyer, I'm sure a lawyer could state why CPAN would be found not at fault. But I'm sure if it came up CPAN would have to remove your modules.)

If they want to submit it as an open-source module, they need to specify that it is being made available under an open-source license.