In fact, us ratifying our copyright term extensions to theirs creates investment opportunities for Canadian publishers to administer the rights on American copyrights for the full term allowed, whereas, as it stands now, you could have a work approaching public domain, which would happen sooner in Canada than in the U.S., and that would be a disadvantage for a Canadian publisher. They would not be able to collect and administer the rights for the same amount of time that a publisher in the U.S. would be able to.
On February 26th, 2020. See this statement in context.