- Ascended Fanon: As stated under Word of God, the film's writer Tim Sheridan mentioned in a tweet that he counted the ship captain from "Ship of Ghouls" as a ghost from the Chest of Demons, which suggests that the long-held speculation among fans that the ship captain was one of the 13 ghosts is now canon.
- Executive Meddling: Again according to the film's writer there was debate within WB when they wrote this film whether the monster should be real or not. Apparently the end result having changed several times during production until it was agreed upon there would be both a "supernatural" explanation and a "realistic" explanation. However due to some of the lower examples listed below one gets the impression some things in the film would have been very different had this trope not been around to forcibly change some events.
- God Does Not Own This World : Neither Tom Ruegger nor Mitch Schauer, who produced the original series, are involved in this project.
- Meaningful Release Date:
- The trailer was released on November 7th, 2018, thirteen weeks before the movie would be released.
- Though not advertised as such, the movie comes out in 2019, the 50th year of the franchise's release.
- The Other Darrin:
- Playing Against Type: Given that two of David Herman's more well known roles are of incompetent authority figures with their own personal issues, him voicing the sheriff at the beginning of the movie, who's competent and stern yet fair, is definitely unexpected.
- Promoted Fanboy: Tim Sheridan loved the original series, and, to paraphrase what he said, practically leapt out of his chair when being asked to write a movie to conclude the series.
- Role Reprise: Maurice LaMarche previously voiced Vincent Van Ghoul on Scooby-Doo! Mystery Incorporated.
- Sequel Gap: The 13 Ghosts of Scooby-Doo began and ended in 1985, while this movie, the conclusion to that series' story, came out in 2019, making for 34 years between the entries.
- What Could Have Been:
- Word of God:
- Tim Sheridan mentioned that the ship of ghouls produced one of the ghosts which would seem to confirm the long considered theory that the ship's captain is officially counted as among the 13 Ghosts.
- According to Tim Sheridan, the movie is canonically after Scooby-Doo on Zombie Island in the timeline.
Trivia / Scooby-Doo! and the Curse of the 13th Ghost