Short answer. If it does not say 'Scale' it is not scale. If you are looking at the freight cars sold in the 90's forward they are more or less like the Lionel 6464 or K-Line 6400. Could be wrong but I don't recall Williams making 'Scale' freight cars. Edited, oops except for the brass set.
I am always puzzled why people think when the maker inserts the word 'classic' it somehow implies 'Scale'. To me it means they are producing the same size cars we had back in the post war period.