Warning: this article contains spoilers for Wicked.One of the biggest strengths of Wicked is that it manages to follow the story of the musical quite well, although a change makes one character more important. While its story largely sticks to the canon, there are plenty of changes that were necessary simply due to the change in medium from Broadway musical to film, and many of them enhance the story being told even more. One of Wicked‘s characters, who was still great in the musical, is even better thanks to a major change to the film’s story.

https://screenrant.com/wicked-madame-morrible-change-better-explainer/