What happens if Teacher changes/deletes a MyCourses calendar event which has been created via Oodi?

Once every night the MyCourses Calendar event¹s type, room, building, subject and time are overwritten with current Oodi information. However, if modified by teacher, the  event¹s description will not be overwritten. In other words, if somebody deletes/modifies an Oodi-generated calendar event, it will come visible again in 'Oodi-form' the next day;  excluding the event¹s MyCourses-description field.