I guess Dawkins doesn't care much about the forums because user generated content is dangerous to handle, especially when your full name is associated to it in the URL.
The ex rd.net forum admins should just register a new domain to run their own atheist forum, then kindly ask the rd.net people to set up a simple redirect from forum.richarddawkins.net to the new one.
Dawkins does care about the forum, he made a statement 2 years ago about how he likes the atmosphere there.
The redirect idea will never happen, as the link on the OP explained the people running the forum are doing everything in their power to prevent anything like that happening in the first place.
I cant believe how they treated everyone! I hope Dawkins is innocent otherwise he has lost all my respect.