Employer's Discretion in Notice Period Buyout
As far as the interest of the organization is concerned, the employer is typically considered the superior party in the contract of employment. This is why an overriding discretion is vested in the employer to either accept or reject the buyout option of the notice period by the employee in the matter of resignation. Whether the reasons are feigned or real, the employer can exercise this discretion as they see fit, ostensibly in the interest of the organization's work.
Therefore, if the likelihood of the employer rejecting the buyout offer is high, the only viable option for an exiting employee is to plan their exit in such a way that they serve most, if not all, of the notice period.