Will there be a short message notice when the time of booking air tickets online has changed?

This question depends on whether the ticket office where you bought the ticket is formal or not. Theoretically, after receiving the notice of flight change, the regular ticket office should immediately inform the passengers by telephone, SMS, etc., and the person in charge should also ask the passengers about the handling of the ticket after the notice, whether to refund the ticket or reschedule it. But these are all manual operations, and we can only say that we should notify them, but there are inevitably exceptions, such as not being able to send short messages, such as the Communications Administration's strict requirement not to send short messages in groups. Even at midnight 12 o'clock, the flight at 6 o'clock in the morning is delayed. The ticket office is closed at this time. Who will inform you?