> 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.