I would not count on on ordering dinner items at lunch. The restaurant only has limited kitchen space and staff which would be taken up by lunch prep during lunchtime. Looking at the dinner menu, the dinner entrees and sides require very different ingredients from the items on the lunch menu. Some probably aren't prepped until the afternoon so I doubt they would be available at lunch.
If the Sticky Wings are the ones on the appetizer menu, you can order anything you wish when paying out of pocket so your son would be able to order those. Just let the server know he wants them as his entree so they aren't brought out as a first course.