r36, From my experience of commercial confidentiality...

r36,
From my experience of commercial confidentiality agreements, they last for ever, at least in theory. There is no expiry date. These are not like government information with a lot of legislation surrounding them such as freedom of information. At the time such agreements are signed, everyone is focussed on the negotiations and just sign a simple plain vanilla agreement and there is most unlikely to be a clause allowing disclosure at a later date. That is just the way these things develop, all just in my experience.