The bottom line for me is that there’s no easy, obvious answer for kids like this. Support them academically and you risk missing out on opportunities for development in other areas. Put them with same-age peers and not only are they likely to be seriously bored but they’re not likely to fit in socially anyway.
As @SatchelSF notes, the boarding schools appropriate for the merely gifted, like Andover, St. Paul’s or Cate don’t want to be responsible for an 8 year old living with 14-19 year olds. Living at home while attending college or a school for the gifted seems like a good choice, particularly if it allows them to participate in same-age peer activities like sports, clubs or volunteering.
My discomfort wasn’t necessarily with the path this family has chosen but with the hullabaloo over the whole “youngest to…” thing. I think it frames education as a competitive sport instead of a way of supporting the growth of this kid and others like him.
Some profoundly gifted kids seem to do quite well later while others burn out. It would be interesting to see a study of the factors that push kids one way or another and how kids who end up later performing at the level of the just really smart end up feeling about themselves and their lives. Are the majority of them happy to have a more average life or does that feel like failure after all the early fuss over their prodigious talents? I imagine such studies have been done-has anyone seen the research?