Sure, it’s a very subjective term. But if you read even the oldest laws which we take for granted, those concepts (such as “reasonableness”) are designed to be open to interpretation. If someone were to stand trial for this, it would be up to the Court to determine whether what they said satisfies the definition provided by the legislation, and that in and of itself is a lengthy process that is designed to be as just as possible, which I can say with some certainty because Canada’s rule of law is relatively good. There are absolutely merits to the policy considerations of this term but what statutory interpretation guidelines haven’t covered, the case law will eventually iron out. In any case, this is not the type of vague wording which triggers an Orwellian collapse.
The vagueness is the step towards it. And it's easy to think about cases where the vagueness might be. For example: opinions for and against the conflict between Israel and Palestine. Or choose some other splitting issue in society.
A change in government to another party may use the same law but in opposite directions to what you or I might think is acceptable. Will one be able to speak truth to power if the power says the truth is harmful?
There are of course going to be many clear cut cases in this new law. I would even go so far to say the majority of them are going to be obvious cases of hatred no matter what politics and beliefs one has.
But almost all of these cases will be covered by existing laws! It's already illegal. So why the new law? What's it really about?