Ear cartilage grafts used for augmentation rhinoplasty almost always permanent.
I don't think you have much to worry about. Most cartilage graft to the nose do not resorbed. Bone grafts on the other hand will resorbed.
Cartilage grafts in rhinoplasty are stable
Cartilage is unique in that the cartilage cells are quite stable and resist resorption very well. The cartilage is circulation independent, shape stable, soft and pliable and ideal for creating nasal shape and support. Your cartilage grafts will stay for a lifetime.