In my opinion you've got a bigger chance of the old textures returning than lighting/shadows, as that would be the easiest, most logical scaling downgrade. Removing specular/normal maps from textures and decreasing resolution would save a lot on processing cost. It's why when you take a PC/console game the boost to textures and effect layers is immediately noticeable.
I don't actually think that will happen though. A lot of that data probably doesn't exist or wasn't made for the full game, so they've settled on this quality.
Lighting is a huge one because it seriously seems like the light rendering engine itself was totally overhauled. Not a case of simplifying, but basically going "fuck it" and baking a ton of shadows instead of rendering everything in real time. I figure Dark Souls 2 PC will ship in the same state.
Hypothetically if Dark Souls 2 PC does launch with both the old textures
and old lighting/shadow system, it will probably be the most impressive port quality turnaround from any developer ever

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I love you too.