That's not recursion. And reversing arrows on this category turns base cases into co-base, or start cases, (and these are still often called base cases in the literature), so it is still required.
Reversing arrows again, back to recursion, you have exactly the standard labeled bases case (well, cases in your code), and reversing arrows doesn't magically change algorithms or invent new structure, so it completely equivalent in the category.
For that code, the 1:1:... is exactly the terminating/starting point, reversing arrows in the category does nothing to change the requirements.
Reversing arrows again, back to recursion, you have exactly the standard labeled bases case (well, cases in your code), and reversing arrows doesn't magically change algorithms or invent new structure, so it completely equivalent in the category.
For that code, the 1:1:... is exactly the terminating/starting point, reversing arrows in the category does nothing to change the requirements.