The difference is between a priority and a preference given in the legislation. Before that, in the Public Service Employment Act, the priority was given to veterans and their survivors, but as stated in the definition at the end, it only applied to veterans of the Second World War. After the Second World War, spouses of deceased veterans were eligible for this preference. Now it's only the regulatory priority that applies, not the statutory preference.
On October 27th, 2014. See this statement in context.