The AppleTV 3 preset is still valid for the ATV 4. The only change between both ATV is that the new version supports level 4.2 of H.264 while the previous version had only support up to 4.0 (so you can change that when using the ATV 3 preset). Also, the ATV 3 preset will limit the framerate to 30 FPS, but the ATV 4 supports up to 60 FPS. Nothing else changed.