Personally I wouldn't bother wasting time trying to get information out of courier companies at this point; you could end up with a version of a version of what somebody thinks is likely to happen. These people, regardless of how high up they are in the managerial chain, aren't legislators. I also wouldn't get too wound up over discussions by or around eBay at the moment. As 'reallynicestamps' pointed out, the USMCA is, at this juncture, only an agreement, essentially a joint memorandum on the desired terms, not law in either country.
The agreement still has to be reviewed, written in legislative language, ratified and passed into law in both Canada and the U.S. In view of the looming U.S. midterm elections, it's not unthinkable that the U.S. Congress might balk if Democrats have more seats, forcing a whole new battle with Trump and putting the entire thing on hold until the 2020 U.S. election. Or the Republican-held congress and senate in the U.S. may ram it through, only to have a Democrat-held congress overturn it, rewrite it, or stall its implementation somehow.
Here in Canada it's also possible (although not likely, since the government's own minister was in charge and they hold a majority) that certain factions of Parliament might want some revisions, which could lead to delay.
Frankly, our Prime Minister is in a extremely tough spot politically with this. He's caught between Trump (and the current Congress) on the one hand, and the general Canadian abhorrence of being bullied by Trump into a treaty that nobody here really wanted to revisit. As Pierre Trudeau once said "It's like sleeping with an elephant" -- and that was when U.S. politicians actually treated Canada as a trusted and valuable ally. All we have to do is consider what Trump has already done to Canada's aluminum and steel industries, and the sort of retaliation he's hurled at China, to be very, very concerned about how delay on our part would be seen by Trump. This will, after all, be one of the things he'll want to tout as his "great deal-making" to bolster support for the impending congressional elections.
So although Trudeau might feel he must get this USMCA passed into law in Canada while Trump has an eye on him, I have no doubt he'll be watching its progress in the U.S. very closely. If they can't get it through quickly (i.e. if Democrats take back the U.S. congress), I'm convinced our government will hold off pushing it through to law.
But I digress. If I were in your shoes right now, I think I'd try to relax and wait until the whole thing is passed as law in both countries before making any radical changes to your business. If and when that does happen, legislative writers will include proper definitions of terms in the law, so that everyone will understand what is intended. In the meantime: "Carry on Canada!".
