While the Wasp and Black Widow more than likely won’t have any scenes together in Avengers 4, it seems that Captain Marvel and the Wasp will.
While that’s still trying to be figured out at the moment, Evangeline Lilly confirmed that Captain Marvel and the Wasp will share scenes together in Avengers 4, which is a pretty big deal.
The Quantum Realm from Ant-Man and the Wasp is expected to play a major role in Avengers 4 and even Captain Marvel, which would explain why the Wasp and Carol Danvers have scenes together.
Captain Marvel is going to be the new face of the MCU starting with Phase 4, which means that we’re going to see a lot more of Brie Larson in the years to come.