For organizations like Alumni groups, being able to maintain a person's names and genders is very valuable. Each person record would need valid dates and a link to their original person. This is important as different people may remember someone by the name they were using when they both at the institution, but wants to find them in the alumni list now. In this case, it is important to maintain not just current and original name, but all names that the organizations has known, since a person might have had several different names while affiliated and connections could be made during any point.
This feature works as well with historical relationships.