No, I think maybe you have it backwards. The screenshot I posted shows that "Tegra B" (one single CPU) is meant for the "Autopilot UI" tasks. I think "Autopilot UI" means the graphical user interface virtualization on the IC, like the toy cars, fancy speedometres and minority report maps.
"Tegra A + dGPU" seems to be meant for the "Driveworks" stuff. Driveworks is not the UI, instead it's the middleware for all the sensor processing, sensor fusion, computer vision and deep neural network. Granted, it's an SDK, but that PP-slide makes me think that one of the CPUs could/should take care of the dashboard 3D rendering, while the other CPU is supposed to be laser focused on the self driving tasks only -- with the help of dedicated GPU(s).
Or am I reading too much in to that diagram?