After looking at the comparison pictures I think I've found out the main reason behind the downgraded look : parallax (or something similar). Here is an example of what it does :
As you can see it turns a flat texture into something awesome. How do you do that ? Well from my experience it's just a complementary file that comes with the texture and which creates that effect (further explanation : the mesh links to that "parallax" file). So it would be 100% consistent with CDPR announcement that textures are identical to all platforms because parallax is just an additional layer that you can include or not (I'd guess consoles don't have that particular parallax file).
Now give a quick look at this, especially the building on the right, and you'll see that the main difference is texture depth :
http://polygamia.pl/Polygamia/51,96455,17905381.html?i=3
On the above picture you can see depth, the building looks awesome and real. On the lower picture the textures are identical but it looks flat and "gamey".
Same goes for the wall on the left here :
http://polygamia.pl/Polygamia/51,96455,17905381.html?i=1
If you multiply that parallax effect with all the textures ingame you can have a quite different experience. Of course the lighting is also different and might not be to everybody's taste but that's easily fixable with sweet fx.
Now I'm not sure it's an explanation for grass too but at least it can probably put some light on a few things and the overall downgraded aspect.
And as a final point, a lot of cool effects like volumetric clouds, fire smoke or animal furs come from nvidia (see this :
https://www.youtube.com/watch?v=3SpPqXdzl7g) so it would explain why it's not on the latest trailers : 1st because consoles are on amd hardware (not nvidia), and 2nd because they want to show the game as it will be played by the majority (parity thing).
Call me an optimistic but overall I believe the vgx trailer look will be mostly achievable, with a few downs here and there probably.
, like the same principle (lightin filter) is used on W3 clouds. It is a flat texture (with alpha chanel) I guess, but with some "filter algorithms". I can be wrong anyway.
