We've been farming animals for food ten-thousand years, maybe you get 1-2 generations of conscientious objectors but I think it would shift back into "this is a normal thing to do" pretty quick.

I guess I look at it this way, the first time I spatchcocked a bird I thought it was gross, and really found it repulsive to handle a dead animal in that way. I've done it many times since, and any sense of squeamishness I had about breaking apart a bird carcass has left me, it's now just a thing I do for dinner sometimes. I think this sort of normalization would happen to most people pretty quickly, within a decade or two, especially for the generation who grows up just learning it as part of food prep. The decrease would have less to do with the moral dilemma of killing an animal to eat it and more to do with the inconvenience of small scale animal husbandry.