This is an unusual provision. I am not aware of any other similar provision in any of Canada's FTAs that would impose a restriction on the global exports of a commodity.
It was concluded in the context of this agreement because it was the best option we were able to identify to address a specific concern, which the United States had been expressing throughout the negotiations and, indeed, prior to the negotiations, that was linked to the introduction of dairy price class 7 and the national dairy ingredient strategy, which came into force in Canada in February 2017.