With Elon's "the best service is no service" mantra, certainly 12v battery failures create a *lot* of service requests.
If the 12v was added to resolve issues of draining the traction battery, then they should be able to bypass the 12v when it's dead.
Certainly opening the tow hook port and using a 9v battery to pop the frunk isn't the best they can do. If they already had the roadster functioning without a 12v at all, they could just bypass it when dead and issue a persistent error... and make it *really easy* to self service.