Looking at the comparison here Nightborne actually look younger, regardless of the mouth thing.
The thing with Nelf faces is that only one is a “young” looking one and even that one is angry. The rest all give the same weird angry old jungle man vibe even if they are different.
And ultimately while NB were never shown to look younger, even in their OG NPCs. Nelves did have NPCs and art where they looked better, so the race’s fantasy from WC3 is not fulfilled.
Same TBH. Fem Nelves have one good face nowadays , but NB faces have a more interesting look and charm. With the eyes squinted, they are just plain hotter.
Of course al the night elven models have weird bodies.