Whatever. The point isn't what they have to fix first or second, just that they need to implement Day/Night.
I disagree. We don't need "obscured by shadows" creeping into the rest of the game just because they make it dark outside. They need to fix that problem before implementing something that will exacerbate it.
Alternatively, implementing a Day/Night cycle will make it very apparent that "obscured by shadows" is a problem. Whereas now, since most of the map is above ground during the daytime, it's a less prevalent issue.