Not to worry, Guy. In the conservation world, we usually don't promote planting any non-native species. Pointing out the obvious, the Chinese chestnut is not native to your region or mine, though I doubt it will be an issue for you.
We have a lot of non-native plants that have gotten way out of control in my area (bush honeysuckle, autumn olive, phragmites, garlic mustard, etc.) as I'm sure you do, too. So much effort is spent just trying to eradicate these plants. They have a variety of issues- outcompete native plants, introduce disease or pests, develop shallow root systems that cause erosion, the list goes on and on.
I don't know that there is any particular problem directly with planting a chinese chestnut. It's just in the grand scheme of things, I think the forester feels that people's time would be better directed towards the American chestnut restoration effort- like what George is doing.
We also got to keep in mind that this isn't the tree planting police, and I think you are better off to plant a chinese chestnut than planting no tree at all!
"Knowledge is power. Arm yourself."