It changes things considerably whether livestock can be raised ethically. If they can, we can try to do that. If they can't, then the only ethical solution is to stop raising livestock. So discussing that 1% has practical implications.
I can't picture the day where people stop eating meat. It just won't happen, not matter what arguments you present.
The best way to go is replacing it, and the perfect postulate is lab meat, which I hope, is going to be massively produced at low cost in the next ten years. And even if it doesn't ill people, tastes the same as natural meat, you will find resistence.
So, to summarise: lab meat at lower cost than natural meat, demands plunge, billions of animals are saved every year.
A less vulgar correlary is that once horse racing is outlawed, horses will mostly go extinct as well, as the racing industry is responsible for being able to acquire feed/hay/veternary care for the average horse owner. Without it will be practically impossible to keep 'pleasure' horses.
We humans are nasty creatures.