if the objective of this is to make the car cheaper, you shouldn't really expect Renault to abuse this. If it isn't, then someone else can come in and offer a cheaper package.
I feel like if I were to make a same form-factor battery for a car I'd get sued on design patents. Cars have always had super tight vertical-integration. It might change, but this situation is pretty close to the status-quo.
Cheaper at the onset does not imply cheaper overall. Renault is already fleecing their customers with one of the highest maintenance costs of all makes (higher than BMW for instance).
I feel like if I were to make a same form-factor battery for a car I'd get sued on design patents. Cars have always had super tight vertical-integration. It might change, but this situation is pretty close to the status-quo.