I wouldn't dedicated too much effort to the Old English Wikipedia if I were you. Who's going to read it? You're just producing learning aids for people learning the language, you're not really creating an encyclopaedia.
So much for creativity and innovation, Thomas :-(. A person is usually advised not to attempt something because of possible negative effects and/or outcome. Is that the case here? I think not.
The negative effects are the loss of his time. That's only really a negative effect for him, so if he wants to go ahead anyway, I'm not going to try and stop him, but if I were him, I wouldn't waste time on it.
Sounds like a worthwhile project to me.
What will it achieve? In particular, how will it further out goal to provide the sum of human knowledge to people?