Mr. Grooberson: There hasn't been a ghost sighting in 30 years. New York in the '80s... it's like The Walking Dead. Your dad never mentioned this to you?
Callie: It's just my mom.
Trevor's classmate: What are you doing here in Summerville?
Trevor: Honestly, my mom won't say it, but we're completely broke. And the only thing that's left in our name is this creepy old farmhouse my grandfather left us in the middle of nowhere.
Answer: Yes, it is still canon. Director Jason Reitman has confirmed it is, and there are actually lots of easter eggs referencing it in "Afterlife." For example, Ray still has his bookstore from "Ghostbusters II." The "dancing toaster" is in the farmhouse. Etc. They chose not to directly reference it in dialogue since it didn't have much to do with the plot, but there are plenty of hidden details confirming it is still canon. Reitman has also said that there are plans to possibly bring back more plot/characters from "Ghostbusters II" in the future. (It just depends on what direction the sequel ends up going in).
TedStixon