Here's why actress P.J. Soles passed on a Halloween H20 cameo, but later returned for Halloween 2018. The original Halloween started life as a low-budget horror movie dubbed The Babysitter Murders and was directed by John Carpenter. While it was initially greeted with harsh reviews it became a word of mouth success and kicked off the slasher movie craze of the 1980s.
In addition to Jamie Lee Curtis returning for Halloween II, she fronted other slashers like Prom Night and Terror Train. While the 1980s gave birth to many slasher franchises, Carpenter wasn't keen on churning out Halloween sequels. After "killing" Michael at the end of the second movie, Halloween III: Season Of The Witch was an attempt to turn the series into an annual anthology. Lukewarm box-office and an audience backlash to this Myers-less proved this wasn't the way to go, and Michael has featured in every entry from 1988's Halloween 4: The Return Of Michael Myers onwards.
Actress P.J. Soles has a couple of horror classics from the 1970s to her name, including Brian De Palma's Carrie and Halloween. She played Lynda in the latter, Laurie's close friend who is later strangled to death by Michael. Given her fate, it was a given Lynda wouldn't return for any sequels but Soles later came back in 1981 to film an additional scene for Halloween's TV version, which needed extra scenes to pad out the runtime. When Jamie Lee Curtis returned for 1998's legacy sequel Halloween H20, Soles was also offered a role.
She was offered the part of Norma in Halloween H20, who is Laurie's - AKA Keri Tate's - secretary at Hillcrest Academy. Even the character's name is a nod to P.J. Soles' role in Carrie. She passed on the part, however, feeling it would be odd to reappear in the series as a different character. The role instead went to Janet Leigh, Jamie Lee Curtis' mother and star of 1960's Psycho, which gave her scenes an extra meta touch.
P.J. Soles may have passed on Halloween H20 but she was eventually lured back for Halloween 2018. If she turned down H20 over concerns about playing a different character, her role in Halloween 2018 makes totally sense, since she doesn't actually appear onscreen. Soles plays the unseen teacher in Allyson's classroom, which mirrors a similiar scene from the original film. While Soles didn't appear in Rob Zombie's 2007 Halloween remake, she did have a small role in his horror Western The Devil's Rejects.