It appears the lighting issue that was spotted in the patched version of PS4 is nothing more than a bug related to the game’s TOD settings. This bug affects all platforms, and can be easily replicated on all of them. And given the fact that the patched version of PS4 suffers from it, we can safely say that it won’t be fixed on the PC via its upcoming patch.
For some unknown reason, the lighting in that particular indoor area is somehow attached to the game’s TOD settings. The ‘pre-patch’ image can be produced by visiting that room in the afternoon, while the ‘post-patch’ image can be produced by visiting that room in the dusk.
NeoGAF’s member ‘Deepo‘ has provided this information, as well as images to back up his claims. And we can confirm that the lighting does change due to the game’s TOD settings.
In short, this is a bug that has not been fixed yet, and can be easily reproduced.
Here is hoping that Ubisoft will fix it via a future update!