Questions on automatic communications to applicants

If we set Oracle to automatically close a requisition once filled, would there be anything that automatically triggers to applicants? Meaning, would they receive a rejection letter when this happens? Would they receive the job has been closed? anything like that? At times someone may accept the job but decide otherwise even before they start. In this case, automatically closing a job req wouldn;t be beneficial if applicants receive any time of communication when that happens. Thank you in advance!