The key issue here is that industry sources have noted that Apple may buy Samsung OLED Flexible screens. The flexible and foldable screen are not the same.
While the screen may be able to fold, it does not necessarily have to be used for this purpose, it can simply be a way to provide a better palette on the edges for a smaller frame or curved corners.
The main feature of this screen, in addition to flexibility, is the inclusion of touch sensitivity. This means that the touch sensors are built on the screen so that another layer is not required.
Seeking components that provide more efficient use of space, it seems like Apple is working on improving other areas. This may mean a larger battery, a larger camera sensor or more cameras, or even a new sensor completely.
The new component can also represent a cost savings for Apple. So this can mean a more affordable OLED iPhone.