User blog comment:Geekius Maximus/Reimagined Maps?/@comment-1187559-20130704100348

Black Ops II takes place like 40 years after Black Ops, it makes a form of sense to make the map more futuristic, even the WaW remakes in BO were made to match the time era. MW has always been around the same time period, so they don't have to change art assets since it would still fit. Besides, if they didn't change the art assets everyone would just call them lazy.