As the article said, pork absorbs more flavor from what the pig eats than most other meats. The wild pigs that don’t taste good probably feed on lousy stuff, whatever they come across. Whereas these pigs feed on acorns, among other things.
The free-range raised pigs I’m familiar with get a lot of whole-plant sweet corn (rather than processed field corn), and stuff like watermelon and pumpkin crop leftovers.
Wouldn’t take many pigs to destroy a large area if they were truly left to forage for themselves.
If feeding pigs acorns gives them a better taste, why can’t some enterprising person grow oak trees for maximum acorn production and sell them to the pig farmers?