That is just not the case. Hunter gatherer societies have rich narrative traditions around every kind of animal imaginable.

You only need desensitization once you are massacring animals on an industrial scale.

What exactly is not the case? Most humans have been dependent on animals for their diet. Even with rich narrative traditions, they would still have to limit their connection to the food, otherwise they would not eat it (similar to some people today). It is abnormal to have easily available food in part due to specialization (butchers, etc) and industrialization.

Are people likely to be desensitized by not being part of the process of getting the animal to the table? Possibly, but that is an ad-don to the points I made.

> Today's environment is an abnormality in history (e.g. individuals wanting to be herbivores) created by the excess of food and technological advances we have.

How this is not true of our artificial cities, dwellings, and infrastructure? And what do you mean by "abnormality"? Do you foresee human manipulation of our environment receding toward some less-manipulated baseline? It seems to me that people claiming voluntary herbivorism is "unnatural" (not your word per se) should take a look at everything else around them and realize that human life today is pervasively and inextricably intertwined with the "unnatural", which doesn't seem to cause people to raise any red flags about it.

I don't think it's an "abnormality" so much as a development, just as human civilizations continue to develop.