Previously, a New family will have the name imported as a Male. And can only be modified after importing.
With this feature, the user can indicate the gender while reviewing the submission, making it much easier and avoiding having to remember (and often forget) to do it later.
This applies to new family (unmatched), and allows you to indicate if the submitted name is a "Male" or "Female". For matched submissions, the the current data is not modfieid.