>>35794990Normal was acting as a "Good" type and/or proto-Fairy, I suppose. I mean look at all the Normies that became Fairy, plus Blissey embodies a hypothetical Good type more than any other Pokémon. I imagine it's also meant to tie into Twinz and Girafarig being Dark/Normal.
Also, while I know it's not called dark in Japan and Ghost is more often associated with literal darkness, it's worth noting that the TCG has treated Colorless (TCG version of Normal) as a light type of sorts. (Necrozma-GX has an ability called Light's End which makes it immune to Colorless attacks.)