Not true. At most schools a career ending injury puts the player on a medical exemption scholly. Now whether the student takes advantage of this is up to him or her.
Having worked at a HS for 30 years I would guess this is what would probably happen. School Board has to approve the expulsion, which it will. Then he’d be put on a performance contract. This would say he gets another chance but can’t have any further disciplinary problems.
I’m surprised nobody has nominated Wander Franco