Are the orbits of spy satellites agreed with any international institutions (e.g. to avoid collisions) or is it all secret and a free-for-all?
I live in South Korea, according to our media the North filed today with the international maritime organization (UN), why that particular org... I have no clue. SK also said the launch would be illegal and they may shoot it down if they launch it. Doubt they will. Notably China and Russia countered saying it is legal.
As for the legality, that's a UN question. Sovereign airspace plays a role, along with whatever UN Security Council resolutions are applicable.