What happens to photos upload from a family member when he leaves family sharing

Hello everyone, I am considering to enable family sharing for my family. The main concern is that I have a son who is 17 years old. In case that in future he wants to get out from the family, as he will start his own life, the photos uploaded from his device will remain in family sharing or all his photos will move to his own icloud plan that he will buy after leaving family sharing ?