WN1A, while I certainly can't vouch for all canneries, I spent a couple of summers at a pink cannery and I can say that no species other than pinks were canned. Either the high graders or the slimers always removed them from the line, either went back in the bay or home if anyone wanted them. Because they had been seined, they usually made better crab food than dining fare. Seems they almost always ended up at the bottom of the net, crushed.