I think the only question we're not sure of is whether a dormant blade would become momentarily active to fry a wielder - one who is NOT the last in the family's bloodline - who tries to wield it regardless of it being dormant. For example - if Elaith tired to draw the blade AFTER if fell dormant but also AFTER he had a daughter.
I argue it would. The blade is dormant - not dead. Its purpose still holds and part of that is to only be wielded by those of the bloodline who are worthy.