Even if he knew about Azshara’s ego N’Zoth sounded angry about Azshara’s rejection and her telling him that he’d be a God of nothing if he didn’t cave in to her demands in the Warbringers cinematic to me…
N’Zoth seems to be a Narcissist with the typical fragile ego in comparison to Azshara’s strong yet self-absorbed ego that can only be shattered by her being on the brink of death due to losing a fight.