first, i think it's important that these people identify themselves because, second, much of what would go on would credibly fall under behaviour considered to be hate speech in canada. arrests could and in fact probably should be made.
to be prosecuted for hate speech in canada, what you need to have done is incite hatred in a public space in a way that is legitimately political. they won't prosecute private communication, and i think they shouldn't. the law is intended to criminalize hate speech that has political intent, rather than just as somebody's opinion.
canada is about as lenient as it gets when it comes to speech rights, but this is the perfect example of the kind of speech that is in fact prohibited by law in canada and which canadians do not and should not tolerate.
so, they should let them march and prepare to make hate speech arrests and put organizers in jail.