I think otherwise. For example, there are societies in parts of the world that consider it appropriate to eat one's relatives when they die. Yes and respect for one's dead is a universal trait. How that respect is shown is what changes. However that is cultural relativism not moral relativism.
Murder is considered wrong universally.
Murder being the unjustified killing of an innocent moral agent. No society condones this. What some do however is exculde certain individuals from the group of moral agents. This latter is a factual question, not a question of morality per se. This is circular reasoning and a logical fallacy.