Also despite using an adapter + 500mm EF lens + 2X TC the birds they were trying to image were very small in the frame so I didn't feel like it was a really good demo.
And it's not like they were smoothly panning on a tripod or monopod, following a BIF's glide path. The image was bouncing around everywhere. There's no way any predictive autofocus could assist with that. If anything it's impressive how well if working in that situation.