I suspect the knowledge was restricted to the working classes. I suspect that the noble classes didn’t really care about how Norese Greenlanders got their lumber, or how North Europeans got the fish they traded with. They’d much rather know where the Chinese get their silk, where the South Asians get their spices, or where the West Africans get their gold from.
Since the resources coming from the North Atlantic were not that valuable, the knowledge of the lands and culture there stayed with the people who worked it.