There are obvious reasons for not talking about certain types of equipment fit (DAS, etc.) especially in conjunction with operations in particular theatres.
BUT
The apparent unsuitability of the 'short' C-130J (C5) for its originally stated purpose is politically rather than militarily sensitive, as would be questions as to the ability of the remaining C-130Ks to reach their OSD. If the C-130K won't last until the A400M (sorry....) reaches the frontline then there has been a procurement f*ck up, and keeping quiet about it can only protect the guilty!
Asking questions about an upgrade of the remaining Ks is similarly 'harmless' but may be interesting for the light it might shed on expectations as to the ISD of the A400M.
Similarly, asking questions about the suitability of stretched C3s to operate from short strips, and about the availability (and remaining FI) of C1s would probably be aimed at uncovering questions of competence among the IPT and desk officers, rather than at uncovering information which might be legitimately sensitive.