People get contractual golden parachutes in the private sector all the time..
The above is not a "golden parachute." In fact, ERISA prohibits an active employee from receiving any disbursement from the employer's DB Plan without termination first. There is an exception to that rule and it's called the age 70 1/2 Rule (which is a non issue in this discussion)
If that was not the law, then virtually every employee currently of retirement age under their respective employer's Defined Benefit Retirement Plan would be drawing their pensions as well as continuing their employment.....