I would probably down vote that idea. I don’t think it would really fit conceptually in destiny.
Defenders of the free world...defenders of the last city...not sure how it can be more relevant, I mean I'm sure as fk that some old school military shit survived till guardians could find them and rally around the legend of the -x- group.
If bungie decided to create a prequel or some sort of lost faction it might hold some weight, I just don’t think it fits in the game space not to mention the lore. Maybe, but probably not.