We probably would have a lot more 'animal-men' as well, and I could see them becoming the major non-human races. More than likely our 'orc' would be the lizard man, serpent man, or some form of reptillian horror. That seems to be a very, very common theme in the early fantasy fiction.
Flash Gordon's various lion-men, hawk-men, fish-men and such would certainly be a factor. ERB's various Red Men, Yellow Men, White Men and the like would be a pattern for humanish variants.
Hey, another thought in all this. Our make-beleive game is getting started when there has been and is going to be a lot of unrest and uncertainty in the world. Traditionally, these are times when people turn to more escapist forms of entertainment. If D&D had gotten started around this time, it might have become the mainstream hit we would want

Today, it would be a 'tried and true' sort of entertainment like Monopoly.]
This would have had to have been something sold in stores of the time, so.. probably a small boxed booklet set, with only six-sided dice or perhaps some other cheap randomization scheme.