In the Scene properties, you will find the the Photographer Main Camera.
The Main Camera settings will be inherited by other cameras that do not override properties. The goal is to create a hierarchy of settings and share global properties between cameras.
Inherited properties are:
Camera Overrides (World, Frames, Sampling...)
Camera Post FX
Exposure
White Balance
Resolution
You do not have to set a Main Camera if you wish to keep the previous Photographer 4 behavior.
You can also turn a Camera into a Main Camera by holding Alt when clicking on the Look Through button.
The Main Camera will be represented in the Camera List with a M symbol.
If the active Scene Camera is not the Main Camera, the M symbol will inform you that these properties are being inherited from the Main Camera.