Eh, rich people are also better situated to take a gap year in general. Gap years are like entrepreneurship - a thing you can do when you're rich because you're not worried about having enough money for your basic living needs.

For your specific example, I'm not aware of any evidence suggesting Malia wasn't a good student / made bad decisions. Obviously giant leg up from being a first daughter. Given that she would have been going to college in 2016, taking a gap year seems like a smart idea for her just to let the furor die down a bit.