So...if I were to say online that Donald Trump is an absolute disgrace, and people in the US should vote for his opponent, should I be facing charges in the US? Or maybe my comment should just be nuked?
By no means am I arguing that foreign influence is a good thing, but it's awfully hard to regulate effectively.
This article does not say threats were made - it says, "according to Chinese Canadian interview subjects, this invoked a widespread fear amongst electors, described as a fear of retributive measures from Chinese authorities should a CPC government be elected."
That's bad, to be sure, but if there was no direct threat, you're going to have a pretty hard time prosecuting the issue.