There's an economic reward for keeping the pigs healthy enough to be harvested while spending the least amount of money on their environment. If this lowers the threshold for "healthy enough", or allows them to survive in an even worse, cheaper to maintain environment, that could introduce or exacerbate human health risks even if this change itself cannot.
There is also the animal welfare element, that has resonance to a lot of people. I am by no means a vegetarian, do not in principle object to killing animals for food. But the sheer scale of animal suffering in our food system gives me pause. I am reluctant to accept innovations that would allow us to increase the degree of suffering in exchange for an increase in output or decrease in price.
Livestock are resilient and adaptable, and can be miserable and unhealthy while being healthy enough to be profitable. Corporate farm organizations like to claim that farmers have an incentive to keep their animals healthy, but that doesn't mean the incentive is to keep them in tip-top condition. The best ratio of profit/cost might be juuuust above "almost dead." Just as human employers tend to look at the low-cost end of the scale when judging employee cost versus employee happiness/productivity, livestock farmers tend to look to the low-cost end of the scale to improve that profit/cost ratio.
I eat meat, some of which I raise and butcher myself, and I'm not generally a big fan of regulations. But I'd be fine with some tighter rules on animal welfare. What's done to cattle in kosher slaughterhouses looks like unnecessary torture to me, for instance. But if consumers want to eat animals that had a reasonably healthy and pleasant existence and a humane end, it should probably be on them to identify farms and butchers that provide that and buy from them. They do exist, but they're small because most people don't care about what they don't see. I'm definitely not excited about any technology which helps to further hide it from them.
I think that view underscores the differences in approach and beliefs in the US and Europe (not that both views aren't represented on both sides of the Atlantic, just distributed differently). The Europeans frequently have the view: Prove to us that this is not dangerous. Otherwise we prefer not taking the chance that you might be wrong. The US version in our eyes is frequently: "You can't prove it's not safe".
In this case you could risk introducing even worse diseases, who have previous been kept in check by the competition from the viruses you're now eliminating.
Really? You don't see a logical flaw in your reasoning there?
https://molecularsciences.org/content/the-challenges-of-cris...
I've yet to see anyone give anything but unknowns as their answer for why it's bad, or what might happen. Nobody seems to have any specific pathway for bad things to happen in mind.