The situation seems very complex. I can’t answer your poll because it would, of course, completely depend on the individual child. For me specifically, I was not diagnosed in my early schooling years and so was completely mainstreamed and this was great for me, despite my difficulties with it. These guys? Not so much, obviously. As you’ve worked with the twins intensely for such a long time you’re really in the best position to determine this for them. In terms of legal statutes, I don’t know what country you’re in so I can’t even begin to help you there.
So...nothing helpful to contribute, unfortunately. But good luck with it and I hope the meeting with the district went well.