I don't like that her birthmark just vanishes. From a narrative standpoint that feels like her character doesn't get to have a better life and isn't worthy of love and affection unless she loses her physical flaws.
The only reason I wouldn't mind it was if it wasn't a birthmark but something that had just as mysteriously appeared on her face at some point in her past, which I could understand people being freaked out about.
Guess I'm never gonna know unless it gets a full adaptation instead of just a promo.