Family was tweeting that he was released and home due to a medical issue. So that's in the public.
The bigger question is what the issue is. There have been kids who had to come home for some surgery or other issue and it was late enough in their mission that they didn't return to the field, but were physically healthy enough to play 6 months later.
So - I get why the curiosity as to if he'll be available to play next year or the following year.