Couldn't the old owners just open new factory farms and outcompete the now-free range ones by being cheaper?
It doesn't need a billionaire to make this happen (which is why you're confusing me), it just needs culture to change.
Does unregulated Capitalism have the mechanisms to abolish such things with time? If there remain even 10% of meat eaters who want to pay $1 for a hamburger, who can stop the factory farms??
The only thing I can think of is a billionaire buying all the animals the way slaves were redeemed for money in some countries. After that no competing farms could start because they wouldn't have the animals to start with.
They say private ownership of animals will prevent their extinction, like commercial bees. That may be true but what about their welfare?