There is already a predictive path that shows on the reverse camera when backing up. An even more difficult task is trying to back up while connected to a trailer. The path of the trailer is opposite the path of the vehicle; unless you practice regularly it can be difficult and you can get yourself in a position that is hard to recover from in a tight space.
When the vehicle is in trailer mode, it would be extremely helpful to have TWO predictive paths; one for the vehicle and one for the trailer (different colors). That way the driver can visualize the swing of both. That combined with incorporation of the side cameras into one view with the predictive paths also overlaid would give the driver a valuable additional tool.