Why any species needed to be recovered is irrelevant to whether or not we should trust conservationists today.
Quite well actually considering that human population levels require most of the historical bison habitat to be used for food production. The American Bison is not an endangered species.
From Wikipedia: "Recovery efforts expanded in the mid-20th century, with a resurgence to roughly 31,000 wild bison as of March 2019.
[7] For many years, the population was primarily found in a few national parks and reserves. Through multiple
reintroductions, the species now freely roams wild in several regions in the
United States,"