I'll attempt to defend that there are NO genuine moral disagreements.
I'll attempt to defend that we all agree with the following principle:
We cannot violate someone's human rights without really good reason
Any reason would appeal to other's human rights.
So.... Is there any counterexamples?
One possible one are Nazis, they believed we could violate the human rights of Jews. However, this disargeement is about reality, not ethics. The Nazis and I disagree not on the principal above, but one whether Jews are people. So there's no moral disagreement.