If you are still experiencing the low glucose event, then the alarm* would present. If you took action and the event was resolved prior to re-establishing connection, then the low glucose alarm would not present.
*Notifications will only be received when alarms are turned on and the sensor is within 33 feet unobstructed of the reading device. You must enable the appropriate settings on your smartphone to receive alarms and alerts, see the FreeStyle Libre 3 User's Manual for more information.