I don't see this running decently on a PS4 Pro or Xbone X or even on my 1080.
I guess it will be time to upgrade when this comes out.
The scale is what's impressive here but in the video you clearly see some 'tricks' they pulled off with draw distance. The city being cramped and not having to see very far ahead along with aggressive use of LOD's can go a long way.
I can see it running on the Pro and Xbox One X at 30fps or with enough optimization. Base model PS4/Xbox One is an entirely different story.
It looks very impressive graphically but most of that comes from the style and variety. Geometry seems pretty balanced overall and square shapes help there too.
They could also like GTA have less pedestrians on the streets in the console versions.