If true, those are some pretty impressive graphics. However, I suspect it’d come at the expense of controls feeling sluggish - realistic animation means your character won’t instantly move when you push the button/key. As nice as GTA5 and RDR2 looked, I found the perceived input delay annoying as fuck.
The GTA 6 trailer wasn't just cinematics, according to a former Rockstar developer who says "It's really gonna look like this" (www.gamesradar.com)