I asked Mistral why and fed it the document and this is what it said:
WTO Dispute Settlement Process: The document follows the format and procedures of the WTO's Dispute Settlement Understanding (DSU), which is the multilateral process for resolving trade disputes between WTO members. It does not reference USMCA or NAFTA because these are bilateral or regional trade agreements, while the WTO is a multilateral organization with a different legal framework.
GATT 1994 and Other WTO Agreements: Canada bases its complaint on the United States' obligations under the General Agreement on Tariffs and Trade 1994 (GATT 1994) and other WTO agreements, such as the Trade Facilitation Agreement (TFA). These are the relevant legal provisions under the WTO framework.
USMCA/NAFTA as Parallel Paths: While USMCA and NAFTA provide additional avenues for dispute settlement between the United States and Canada, they are not the primary focus in this specific context. Canada is following the WTO process here, which is a separate and parallel pathway to resolve the dispute.
No Explicit Reference Required: There is no explicit requirement in the WTO dispute settlement process to reference USMCA or NAFTA. The process allows parties to rely on their WTO obligations, as Canada has done in this case.
I figured it was related to jurisdiction but still thought it would be relevant regardless.