The reason why the autopsy results are still missing may be explained by the French newspaper
Le Monde (To Be Confirmed, obviously):
Selon un haut magistrat français qui n'a pas souhaité être identifié, les autorités brésiliennes refusent de transmettre leurs conclusions portant sur 51 corps retrouvés dans l'océan Atlantique car elles n'ont pas encore ouvert d'enquête judiciaire mais seulement une procédure administrative.
In other words (thx Google Translate): Brazilian authorities refuse to forward to the French the autopsy results because they have opened no penal inquiry yet, the ongoing procedure only being an administrative/civil inquiry.
Obviously, this news is dedicated to Will Fraser