What's been established according to Dembski is that the idea has religious implications ("penumbra" is just your own term). The same can be said of Darwinism.
Most Darwinians are theists. The theory of evolution has religious implications in that it disallows literal readings of the Bible and Koran, but then so does much of physics, geology, astronomy, etc.. Simply because a religion makes highly implausible statements about the state of or history of the world, does not mean that any science that contradicts those statements is intrisically religious.