As someone who has been out of the forces for a number of years, I obviously cannot comment on the current situation. However, the Act does contain the following caveat:
Information is exempt information if its disclosure under this Act would, or would be likely to, prejudice-
(a) the defence of the British Islands or of any colony, or
(b) the capability, effectiveness or security of any relevant forces.
(2) In subsection (1)(b) "relevant forces" means-
(a) the armed forces of the Crown, and
(b) any forces co-operating with those forces,
or any part of any of those forces.
Which I believe could be construed as a convenient get out clause??