It was uncertain whether the fairy tale was an original because there was not enough information to determine whether it came from a specific work or author. Comics are usually created by cartoonists based on their own creativity and inspiration. They can be based on existing stories, novels, movies, or other works, or they can be completely new storylines. Therefore, to determine whether a comic was original or not, one needed to look at the source and background of the comic to determine whether it was based on a particular work or author.
The 'The Devil Is a Part-Timer' manga has come to an end. The final chapters wrapped up the plotlines and provided closure for the characters and their adventures.
I'm not sure exactly when the update will come. You might want to keep an eye on the official manga website or social media channels for the latest news.