Oh yes, yours was a valid theory.
I just an gave alternative reason, not saying you were wrong. I'm not saying one way or the other, just that the epidemic is subsiding and the time is drawing near for ending the mandate. I'm not all that hard up about mandates anyway. Given information out there (not the fake stuff), I could argue either side of the issue and not be wrong. March 1 seems like a good time to lift it. The mandate is in place until then. Setting policy on something we know so little about is fuzzy science. Can't expect much certainty here.
In any case, it's just for crossing the border. Nobody's livelihood was threatened. If the Canadian trucker refuses, they just take loads within Canada. I know in the US that truckers are in high demand. Isn't it the same true in Canada?
The convoy protest wasn't really about vaccination mandates. It was a right wing political theater. If it was about a mandate, why were there so many reports about menacing and acts against people who had nothing to do with the issue? Why menace healthcare workers?