At the last minute last night the US and Canada cut a deal, so now Canada is on on the deal to change NAFTA to USMCA. I think the name change is the biggest part of it, even though Trump still claims that NAFTA was “the worst trade deal ever” and the new deal makes relatively minor changes in it, especially if one considers what would have been the case if the US had actually joined the TPP, as most of the environmental, labor, and intellectual property parts of the new deal (the environmental and labor parts largely improvements, if not too dramatic) were already agreed to by Mexico and Canada when rhey joined TPP, which they belong to along with all its other members aside from the US.
Beyond continuing NAFTA and adding the TPP parts, the main changes are in the auto industry and the dairy industry, the former mostly affecting Mexico, the latter mostly affecting Canada. Between the restrictions on outsourcing and the $16 per hour limit on imports, there may be some shifting of auto parts production from Mexico to the US and possibly Canada as well. This will lead to job losses in Mexico, but there may be some Mexican autoworkers who see wage boosts also. The auto deal has little impact on Canada aside from Trump retracting his threat to impose tariffs, which was opposed by GM and Ford as well as the UAW thanks to the profound integration between the US and Canadian auto industries.