I was assuming the opposite. Keyboard and Mouse is usually regarded as superior to joysticks for FPS so I assumed they were trying to bridge the gap and come up with something more mouse-like?
If it were me doing it, I would use the trackpad and the trackpad buttons. (I'm not sure, but I believe each trackpad is "pressable" and has multiple buttons, replicating a d-pad)
I would tap and drag for little and precise movements, swipe for fast movements, and press the button for default movement. With some training, it can become pretty natural.