Joe,
Thank you for sharing this interesting article. In Europe we act on the same problem but here are rainies and brookies sad to disturb the headwaters of the native brown trout. Our fishery responsibles think that rainbow - and brook trout are much more agressive so that theses fishes shouldn't be releazed in brown trout waters. But there are only a handful waters in Germany for example rainbow trout are able to spawn. That keeps the population in natural borders. I think that we should keep the fish population in the headwaters as natural as possbile.
If we fisherman want to catch foreign kinds of fish we should do a cool fishing trip to waters where this fishes are native. By & release is seldom a good idea.
Regards from across the pond
Thomas