The point was, when the function returns, the caller "can know" that some array was returned.
You'll have to explain how, then. The caller can't know that an array was involved because the caller only gets a list of scalar values pushed onto the stack.
By the way, your code examples don't prove that the copying happens before the return. They just prove, that the "for" loop works with copies of values. Nothing else.
Half of the code proves that the 'for' loop gets copies. The other half of the code proves that 'for' loops don't get copies when using an array. That's one of the major features of 'for' loops: They work on aliases not copies when possible. When calling a function, working on aliases isn't possible (because what gets pushed onto the stack is copies of each scalar value).