Firstly, this is not the UK or Wales for that matter and thus those semantics do not apply. The fact still remains that this is a manipulative policy that does nothing more than protect the interests of the company by limiting what previous employees may decide to say about said company post completion of contract. There is no way to defend this policy as any employee is entitled to an assessment of their time at said company that is without bias or malicious orientation. Pity you stepped up, seems you've become K's whore too.