NAFTA 2.0 (I hate calling it USMCA, just like I don't call the airport near the Pentagon Reagan but National--I am stubborn and, yes, conservative, that way) is a strange beast.
It does not radically revise NAFTA, but it is an excellent rorschach test. How one views it really depends on what one is expecting from such an agreement. On the one hand, Canada did not get anything out of the agreement that wasn't already in NAFTA, from what it sounds like. It did give in a bit on a few key things--a bit more dairy access, limits on cars sold into the US. So, that sounds like a defeat--that Canada didn't get much or anything but gave up on stuff.
On the other hand, Canada averted major restrictions on cars and perhaps other sectors. Note the expansion of the US trade war with China to cover lots of goods. So, Canada gave up a smidge of access to the dairy market--something like access to 3.75% of the dairy market compared to 3.25% in the TPP that Trump walked away from--to keep the trade war limited.
Limited trade war? Yes, because we still have the steel and aluminum tariffs.* If Trump rolls that back, then, yes, this agreement is a significant victory. If not, then it is like a mid-war agreement to keep the carnage limited. Kind of like implicitly agreeing not to bomb China as long as China does not bomb Japan in 1951. The trade war would still go on, but it is now less likely to escalate.
* I talked to my colleague, a trade agreement expert, and she argued that this was a bridge too far because Trump's steel/aluminum tariffs aimed at multiple actors, not just Canada and Mexico.One last thing: nothing that Trump says now means that he will follow through. This is both because Congress may not go along AND Trump has no credibility, his word is not good, and he changes his mind a lot.
This was probably the best Canada could do, which is sad to say, but reflects both the asymmetric power relationship and how messed up the Trump Administration is. I doubt any other politicians in Canada could have done this better. I do hope this means that Chrystia Freeland can be the Foreign Minister again and not just the trade negotiator.