The future of the Flying Monkeys is one of the biggest questions after the end of the first Wicked movie, and here is why they will start working for Elphaba in Wicked: For Good after being her enemies. The Flying Monkeys are one of the most famous pieces of iconography associated with the Wicked Witch of the West, with them constantly being by her side in most versions of The Wizard of Oz. However, by the time the first Wicked movie ends, they seem to still be fighting against her, with this change being a major story point in Wicked: For Good.

https://screenrant.com/wicked-2-elphaba-flying-monkeys-work-together-reason/