It is unconstitutional for any part of the executive branch to write laws. It is also pure corruption of the constitution for the USSC to say otherwise. It is also unconstitutional for Congress to relegate their power to any other entity. The founders intended that to be done by representation through congress. Until that truth gets re-established then we no longer live in a constitutional republic.
Title IX itself is unconstitutional. The federal government does not have any authority to regulate how men and women are treated.