>>41383430Nessa's reveal was different because she had more visibility, even to lapsed fans or non-Pokémon fans.
1) Sword and Shield revealed her during an E3 Direct rather than a Pokémon Direct or Official Pokémon video. Basically any fan who had no knowledge of previous trainers with dark skin could EASILY think Nessa was the first if they haven't touched the series since Red/Blue or so.
2) Phoebe, Dahlia, Iris and Lenora had 2D games, which haven't been as expressive. Olympia and Olivia had 3D games but the former wasn't shown in pre-release videos and Olivia was only known to Pokémon fans who were already going to play Sun/Moon.
3) Social media technically was at a high when Black/White was out but Iris had childish qualities and probably wasn't acceptable to swoon over her in the same fashion. Lenora brings "Mammy" imagery to mind so I don't think many wanted a character in Pokémon reflective of unflattering times. Olivia got some notice past her release due to the Brock episode but otherwise is more acknowledged by Sun/Moon players.
It also helps that the presentation of characters in Sword/Shield is more expressive than the chibi dolls in X/Y which didn't do Olympia many favors. Sun/Moon's models were okay but less detailed than X/Y and ORAS' full scale character models. Nessa just happened to have the perfect storm as far as marketing and timing went.
