Liability imposed on this system with respect to the death of a member who is an academic employee of the California State University while on, or within 12 months following, a leave with pay during which the member received compensation in an amount less than the full compensation earnable by him or her when not on leave with pay shall extend to the death of the members occurring on or after January 1, 1973, and to any benefit for which there would have been liability with respect to the death had Section 21533 been effective on that date.