Well I see mostly only these problems: Some of the textures, foliage and maybe a few lighting things. All of these don't suggest downgrade though necessarily, since they could as well be bugs or things deactivated or broken in the current build. Bigger questions is, if they make a video, why they don't avoid footage of currently broken things. I don't expect the game to be perfect currently, while they are still bugfixing and polishing, but to give an impression how it will look without those problems would have been better in my opinion. When you review the trailer before you release it, you should notice the problems and rerecord the scenes. Well maybe they decided to make one just last minute and didn't have the time anymore.