Don't mix two things that have nothing to do with each other: dynamic shadows vs. the brightening of whole areas in general. The latter has nothing to do with performance and has to be a design decision.
The console version still has dynamic shadows. Whether they are there or not is entirely dependent on the individual light source. The torch always casts dynamic shadows, so do some other lights sources. But it's clear they deactivated dynamic shadows on a case by case basis dependent on how performance-draining the respective environment is.
I remember that the area with the bridge definitely had framerate problems in the network test and they obviously felt that it's better to deactivate dynamic shadows there.
I just made a couple of offscreen pictures of the area; also in response to Violater's query:
Sorry for the bad quality, I don't have capture equipment plus I didn't want to waste too many precious minutes of my torch time.
So, since there were no fundamental lighting engine changes but rather a case-by-case activation of dynamic shadows, I guess we can hope that in the PC version every light source will cast dynamic shadows. But I think that the ambience lighting overall will still be brighter since that has nothing to do with performance whatsoever.
edit: Also, it's probably noteworthy that the brazier in the early demo footage does
not cast dynamic shadows; as opposed to the final version where this particular brazier casts shadows. So they probably went back and forth in many of those cases.