I'm not 100% sure whether it's intentional, but I think it makes sense if it is. If females could be set to alliance-only, someone could breed their male to your female before the two of you had actually agreed on the breeding.

Those kinds of arrangements are usually negotiated directly between players rather than enforced by the game itself, and since pups are automatically born into the dam's den, there's not really the same concern on the female's side.

That said, I can check with Eve to confirm if you'd like.