A court order for less restrictive alternative treatment for a person found to be in need of assisted outpatient treatment must be terminated prior to the expiration of the order when, in the opinion of the professional person in charge of the less restrictive alternative treatment provider, (1) the person is prepared to accept voluntary treatment, or (2) the outpatient treatment ordered is no longer necessary to prevent a relapse, decompensation, or deterioration that is likely to result in the person presenting a likelihood of serious harm or the person becoming gravely disabled within a reasonably short period of time.