Ok guys now I am a firm believer, thanks for your patience!
The Witcher 3 on console, like most of you have already patiently tried to assert here, does use a 2x super sampling Temporal AA and it's a very good one, the ghosting effect is not super easy to spot indeed.
That's why the game look so great even in motion, because their temporal AA (and the super sampling effect) is very stable and works even in moderately slow motion with very little ghosting, less than in FC4, their TAA being much more stable (and better) than in AC4 / InfamousSS, and in fact their supersampling is also anti-aliased at the same time to look like 2xMSAA. It's also better than 2xMSAA because everything is super sampled, no only the geometry...
Very ingenious stuff and no wonder it's not really cheap on the GPU, the advantage is that the cost should roughly scale linearly only with the resolution, like all postAAs (costing ~9% of fps
here).
I had to search for the right speed to capture those ghosting effects on my PS4 with adequate high contrasts:
Also it explains the discrepancy of increased clarity of the PS4 1080p image versus XB1 900p image, no need for reduced AF on XB1: textures + chromatic aberration + 2x supersampling at 1080p versus the same 3 features at only 900p; all 3 combined make the perceived clarity difference between the 2 images slightly bigger than usual. Well that's my personal and final opinion anyway.