Okay so, Musica has abnormality that can maintain humanoid form along with intellect, the nobility monopolized human meat, eradicated the cult she made around her and consumed remaining members to gain her ability.
There's nothing stopping them from repeating the cycle as their "religion" or rather "instinct" favour the thrill of hunt.
It's not telling if the human side wouldn't accept the humans back to their side, Norman doesn't know that for sure.
They should make contact with the human side.