If you read the article he recruits kids when they are still in middle school, basically poaching the best students from various other schools to join his high school.

So it's essentially the same as an all-star team, but putting them all together in the same class and recruiting some university-level talent to help teach them.

The article tries to present it as an 'average school', but it's not an average class of kids. That said, it could definitely still help kids who wouldn't have that opportunity at their own schools.