I can think of it happening a few times with things other than sex/nudity: the epic and ongoing SJW rage over the lack of black people in a certain popular RPG series inspired by the history of a country with almost literally no black people,
Whats the name of RPG ??
And you can always count on SJW to provide some epic butthurt.
But that being said, lack of black people is pretty stupid - its not some magical creature, its just human with certain melatonine count so if universe resembles Earth in any way ( round planet, equatorial inhabited regions etc ) it should have black people in some form.
The Witcher series, namely Witcher 3, because that's the one that's currently relevant.
There are a few dumb things about the "controversy".
First, the selection of that one particular game to serve as their
ongoing example of "#GamesSoWhite" (that was a real hashtag campaign, by the way) is bizarre at best and part of some conspiracy against it at worst.
Second, the game's fantasy setting is inspired by a variety of European, especially Slavic/Polish, myths and stories, so having the Token Black in there would be like having one out-of-place white guy in a game based on African tribal mythology.
Third, there are supposed to be non-white humans in the world, and I believe they appeared a few times in previous games and in the upcoming DLC; however, as in the real middle ages, they don't travel to the Europe-analogue serving as the main setting in particularly large numbers.
Fourth, the "Witcher 3 needs black people" crowd loves to cite as their source a very specific Tumblr blog called "MedievalPOC" which uses medieval European paintings, often of scenes set in the Middle East or Africa proper, and portraits of relatively dark-skinned Europeans (Italians, Spaniards, Greeks) in poor lighting as proof that medieval Europe was literally as racially diverse as the modern US.
EDIT: Actually went to check MPOC because I hadn't for a while, and I forgot another source of their "evidence": post-medieval (as late as
Victorian) European art of non-white people.