It is also what Tesla was doing with their old 2.5D labelling. 4D is making a 4D point cloud of the entire video from all cameras to label all frames at once. Not labelling each camera in 2D and stitching them together(in 2D).
Like I said. Maybe Tesla is implementing 4D differently. But if Mobileye has camera vision that can track the paths of objects in real-time in both space and time I consider that to be 4D.