Removing smoking (or alcohol, drugs, swearing, sex, nudity, violence, racism, gambling, slavery, Nigger the dog, etc etc) from films, books, etc already made would be a retrograde step. It's attempting to rewrite history no less than the renaming of streets and towns when dictators and political systems change. What's more, when we see films like that ^^^ where smoking was an essential ingredient in being cool, sexy and sophisticated, we're reminded how experts are fallible too; everybody went along with it at the time. Doctors used to routinely endorse cigarettes! The world changes constantly and if we forget this it's too easy to allow it to change in a bad way, or at least to not try to make it change in a good way.