Even our very own “wild” steelhead are no longer “native” in many watersheds. Hatcheries on the west coast have been around since the late 1800s."Wild" and "native" doesn't always mean the same thing. There's multiple species of wild animals in North America that aren't native but have flourished. All the article is saying is you can take a domesticated animal (hatchery raised trout in this case), release them into a new "wild" habitat, and they'll either eventually adapt (become "wild") to where the population maintains or increases in numbers, or they'll fail and all eventually die off. Same concept as there's wild salmon runs in South America now, but they're definitely not native.