We have to bear in mind that there are principles involved in the application of such a broad act, which applies to all parliamentary and government institutions.
Among those principles is the separation of powers. For instance, Treasury Board cannot be made responsible for ensuring the implementation of parts I and II of the Official Languages Act, which apply to Parliament and its houses, or of part III, which pertains to the administration of justice.
Among the other constitutional principles at play is the concept of responsible government. The minister is always accountable to Parliament and to MPs. Of course the act already includes monitoring mechanisms. With respect to policy, the act relies on the good faith of all ministers and all those responsible for its implementation.
I think these aspects also have to be considered.