This is the 13999th most frequent Russian word.
объявят
"Объявят" means "they will announce."
In this sentence, 'объявят' is used in the context of making a public announcement about exam results.
Завтра объявят результаты экзамена.
The exam results will be announced tomorrow.
Here, 'объявят' is employed to indicate that organizers will inform attendees of changes in the schedule.
Организаторы объявят важные изменения в расписании.
The organizers will announce important changes to the schedule.
'Объявят' in this sentence pertains to the act of declaring or informing the public about the event's date.