Promised Neverland Season 2 is not yet over. It is still ongoing as of the writing of this article. I am not going to provide any spoilers for the people who never read the Manga.
The manga version is a piece of literature that everyone should read. The fans who read the manga have a polarizing opinion about the season of the Anime because it became its own entity.
It didn’t follow the Manga at all and that is because the writer himself wanted the change. Kaiu Shirai decided to change the direction of the Anime because he wanted to keep the tension of Season 1. The Manga arcs that got replaced are more action packed and less horror.
After all, the Manga changes genre into action on the next arc. Also, it gives unpredictability since people who read the manga know what will happen next.
There are anime in the past that didn’t follow the original plot of the source material. Sailor Moon and Fullmetal Alchemist are two big examples. Those 2 titles though eventually had Manga accurate adaptations in form of Sailor Moon Crystal and Fullmetal Alchemist brotherhood.
The Anime is not the only adaptation of Promised Neverland. There is a live action film adaptation made for Japanese Audience. This film is also its own entity because it made major changes like the ethnicity of the characters and they Aged up Emma and the gang.
Amazon Prime got the rights to make a live action adaptation of this Material. Of All the Anime and Mangas out there, this should be easy to adopt for an American Audience. Unlike Death Note, there will be no worries about White washing because most characters are white. I can see the Hollywood adaption being more diverse. They can appease the Manga fans who felt betrayed by the second season of the Anime by being more faithful to the source material. They don’t need to Americanize things because the setting is very western already. All they need to do is make a good casting and a faithful adaptation to the Manga.