Would that ban on stocking apply the the three big dam impounded lakes, as well as Lake Chelan? This (NPS produced [biased?] history includes the statements by the head of WA Dept of Fisheries [factually biased?] that stocking was required for at least some of these lakes) .
http://www.nps.gov/parkhistory/online_books/noca/adhi/chap1.htm
Regardless of one views, the NPS produced history is fascinating, and details the struggles between the USFS+DoAg v. Dept. of Interior+NPS, as well as the personalities of Bob Marshall and Harold Ickes. At one time, the precursor of NOCA was hoped to contain almost all of the North Cascades north of Stevens Pass.
And in contrast to an earlier poster who stated "...Wilderness designation is the gold standard.." the NPS history points out that Wilderness is merely an administrative designation, while NP status mandates the protection and management by an entire service.
Never the less, folks are right to be concerned.