Trump tariffs are based on the International Emergency Economic Powers Act (IEEPA) of 1977, overriding USMCA and other trade agreements. Any renegotiation of USMCA wouldn't stop the potential use of IEEPA to selectively override parts of USMCA v2.

It's more likely that USMCA violations referenced by Carney and Freeland were done by Mexico/China, at the economic expense of both Canada and USA.

All trade agreements are about surrendering some domestic power. What act or other domestic legal instrument is used is irrelavent.

In context it seems very unlikely this is about mexico, as carney is running on a platform of closer integration with mexico and strongly distancing canada ecconomically from the united states. Carney's ecconomic policies are not identical to the previous administration - it makes about as much sense to refer to trudeau/freeland's statements as it would to try and explain trump's policies by referencing things biden said/did.