Edit- oops, should read the question carefully, don't be a dummy like me!
To answer the actual question. The two generations are both x86 from the same CPU and GPU vendor, so just porting it will be fine. But "take advantage" of the next gen consoles?
That's going to take years and years. Figuring out the best streaming schemes for the new SSDs, figuring out raytracing beyond "we made some things reflective", optimizing for the new architecture, for double rate floating point 16bit format, for mesh shaders and variable rate shading and etc. etc.
Just like always games will just look better and better. And crossgen ports won't look that good comparatively. As programming wiz Emil Persson, now working for Epic, put it, you get a lot more effect out of raising the minimum requirements, which is to say moving towards next gen console only titles, than out of raising the maximum requirments. Which is why you shouldn't be surprised to see a bunch of crossgen titles going from 30 to 60fps, raising settings and resolution, having some sort of HD texture pack, but generally not hitting the same visual bar as next gen only titles.