The point is that the planning itself wouldn’t be illegal if there were absolute free speech. Of course the murder still would be, but ideally you’d want to stop that before it happens, which will be tougher when just talking about murdering people is perfectly legal. Free speech isn’t just about “naughty words”.
AFAIK Ukrainians started calling Russian soldiers Orcs and Russia Mordor due to Russia being an invading force with often very brutal tactics and horrible behaviour in the regions they occupy.