This is not new, it’s just the latest round of updates identifying hatchery stocks that are part of the listed salmon and steelhead population. It happens with every 5-year status review, the latest of which (2015) came out earlier this year.

It’s been in place since the final “Hatchery listing Policy” in 2005: http://www.westcoast.fisheries.noaa.gov/publications/frn/2005/70fr37204.pdf