Sure, the employee should question it, ask for the reason for termination. Even during probation, termination should not be on account of "management instructions". If the terms of appointment order says that "during probation your employment/ this contract of employment shall be terminated by either party without reasons and without notice", then the termination letter/ mail should be worded like, "following clause No....(above referred) your service stands terminated with effect from 1st April 2024". This makes sense but no way the wording in the mail like "as per the management instructions you will be relieved from the service". Suppose the employee is a confirmed employee, this kind of mails will not be sufficient but in order to terminate there should be reasons and that reasons should be first made known to the employee, and then following the procedures involved in it.