You know, I'm not even sure it would require a patsy or collusion for WotC to create a lawsuit for the express purpose oof tearing down this licence at a time of their choosing. Part of this licence says that by using any material in this licence, you agree to it; in other words, you don't have to sign it, read it, or even be aware it exists, in order to 'agree' to its terms.
So WotC could sue SJG or GW (or more likely, a one-man-band publisher, as they won't have the means to argue back) for using hippogriffs (very spurious example, but something else might exist). They'll rightly say they never agreed to any such licence, and WotC can then say, oh, that line isn't enforceable? I guess we'll just have to revoke this sucker for everyone then.