No they are not official. They say that they are and they may have been at the time they were published, but they can and do change. Even once disney publishes them they still can and do change sometimes. That has happened several times in August. Disney changes the hours or days of EMH based on crowd predictions.
The 'official' hours should be out in the next few days, but like I said, even then they can change and you should check them again before your trip just to be sure they are the same.