The recorders are at 50m. THe wreck has been dived on by the local professionals. It is just outside the sport diving limit (42m) but easily withing any professionals range using decompression technique and maybe heliox mixture.
It should have been an afternoons work to retrieve them. One can only conclude that the ATSB deliberately did NOT want their contents revealed because it would have given the lie to the story and subsequent fitting up of Dominic James.
If the wreck has not broken up, they are probably intact and readable, assuming they are solid state devices. A private expedition could get them, but my guess would be that ATSB would attempt a legal move to sieze them and suppress the contents if they were retrieved.
I've dived on "Blackjack", a B17, in New Guinea and its still intact at 42m after all this time.