I think there were probably just 2 pictures taken. One had the special needs students in and 1 didn't. I don't think it was being sold as the ASN version and the ASN FREE version, I think that is just someone's interpretation when looking at the image.
Like, when my daughter had her preschool shots taken, there were a few to choose from. I guess the children are more wiggly at that age so each parent would probably just want to pick the image where their child was clearest.
In that example, none of the other children were removed but from the article, the ASN children were still in one of the class pictures, they just weren't in both. So the parents that had disabled children in the class, could still buy a group shot with their child in if they wanted.