George Fayne is reimagined as George Fan, an Asian woman played by Leah Lewis who serves as Nancy's former high school nemesis and diner manager. Ned Nickerson becomes Nick, portrayed by Tunji Kasim as a Black man with an incarceration backstory, while Bess Marvin is recast as Bess Turani Marvin, played by Maddison Jaizani, with her sexuality changed to lesbian and introduced through an early relationship with a woman.

These casting decisions shift the original characterizations in ways that prioritize identity over fidelity to the source material. Showrunners Melinda Hsu Taylor and Noga Landau have stated their intent to pursue a "diverse take" on the novels through an inclusive cast and writers' room aimed at reflecting multi-ethnic America. Bess's queerness receives ongoing narrative focus within the ensemble, marking it as foregrounded content from the early episodes. Although the core premise stays fixed on supernatural mysteries and teen relationships instead of identity politics, the cumulative effect of these changes still registers as intrusive progressive framing layered onto the established framework.