Blender Version All, as I know
Keyframing not possible for Camera switching
So if I want to switch from a camera to another with the Scene > Camera property like in the following image
Almost everything in Blender is "Keyframable" but not camera switching.
I know it is possible to switch from a camera to another into the scene with markers but this workaround is not "immediate" to understand. It seem that blender is incomplete in this aspect. I don't know if it is a bug or it is a "feature" of it. IMHO is an incomplete feature or a bug-like thing. I hope this will be correct in future releases. and the Scene > Camera property will be in the future "keyframeble" as well. It will simplify the job. Of course it could be a further implementation but not a substitution of markers.