Not related to this sad accident but a savvy SAR agency
PR chap would surely find it easier to tell the press that the BLACK BOX has been found even if it hasn't or especially if there isn't one.
Much easier than to try to explain why it hasn't been found and far, far, easier than explaining that there is no requrement for a black box in certain classes of aircraft.
They will regurgitate the news that the black box has been found a few dozen times and then forget about it.
Same goes for Flight Plans. The meeja tends to seize upon the lack of a flight plan as the obvious cause of the prang. Better not to tell them.
Sorry to be so cynical.