I have to say, so what if the press find out? Clearly his PERSEC is extremely important, but no more or less than any other rotary pilot. This is a risk management issue rather than a press management issue.
The well-known fact that he directed air and arty fires as a JTAC in Afghanistan surely means that there are some members of our community (ie the Un-united Kingdom) that would wish him harm. And will serving as an Apache pilot measurably increase that risk?
Anyway, well done Prince Harry. I hope you get a front line tour, deal it to the bad guys and return safe.