Leather does get softer as they become worn, takes years for that to happen. They also become cracked from aging, but if they are well taken care of (all my leather jackets are for instance), but if they are soft when bought, they will remain softer when aged if not worn. Mine are not!
Nubuck leather have been sanded, making the cattle leather softer. As for soft vintage, they are probably treated. I have no idea how each differ, best answer is just call the Customer Service.
I don't make the shoes. I've seen leather shoes or boots, that looked rugged, and those styles are coming back, because people want that old worn look.