Hmm your mistaken, as there is no explicit right to protest, guaranteed in the Charter only a right to peaceful assembly, any protest that took over a street without a permit to do so would be a breach of the peace, under common law, with the right for police to arrest without charge.
I imagine BLM were rather hoping for this sort of confrontation with police & the police used their discretion rather force the confrontation, brinkmanship one would suppose.
Courts have broadly understood rights to freedom of expression and freedom of assembly to guarantee a right to protest, which in any case existed before the charter itself.
These rights are not absolute, and can be restricted within “reasonable limits prescribed by law as can be demonstrably justified in a free and democratic society.”
That's obviously fuzzy but there's lots of precedents for street protests being found to be legitimate and therefore constitutionally protected.
Police and courts will seek to figure out what those reasonable limits are so that the protesters are able to exercise their right to express themselves without unduly infringing on the rights of others.
There are some clear lines around violent behavior. The police can and will suppress anything that makes others feel unsafe or threatened. Typically by separating the protesters from those who might feel intimidated. Or if that isn't working by reading the riot act and dispersing the protest--but that needs to be justified by a real fear of violence.
Assuming that nobody is being threatened the police will seek to limit how many streets are blocked and for how long so that the protest can continue while others are only moderately inconvenienced.
