Oiling knives used to be common before stainless became popular. Now most knives are stainless.
My first few knives in the early 1980s, like my old Cub Scout and Boy Scout knives, were carbon and had to be oiled.
Many of my fixed blades are carbon, but I generally keep them clean and dry rather than oiling them. In the past 15 years or so I've mainly just oiled the joints on a few folders. Coated blades cut down the need for oil.
Since the majority of knives used to be oiled, if there was anything to the theory that oil makes worse wounds, it would have shown up in any knife injuries back before stainless became dominant. Most knife injuries are self-inflicted accidents, and I'm sure that a number of them were caused when sharpening, and it used to be popular to sharpen knives on stones lubricated with oil. Many still sharpen that way.
