Moving content between wikis is a challenge. Obviously permission may be sought and granted. We hope there'll be lots of GluePeople who grant permission for all their words to be used in both wikis. Alternatively ideas may be rewritten to move between wikis. However, the plentiful use of NearLinks renders this unnecessary in 99.9% of cases, so there's very low overhead. The open content side can also license all its text to be moved to the default copyright site, as CommunityWiki does for meatball.
In theory, by allowing people to choose their copyright policy, you EnlargeSpace to defend against copyright-related divisiveness (DefendAgainstPassion), without weakening the community to forks in general. You deal with conflict internally, by subsuming both sides of the argument, rather than picking one side of the argument and then defending against external conflict.
But, forcing people to think about copyright when adding or refactoring is a hindrance to submission: it's not a HumaneInterface. Also, the duplication of content violates LessRedundancy. In essence this approach prioritising the desires of copyright idealogues (both open content and closed content) above those who just don't care. This is a ring coalition, and as such is unstable.
The above text is PrimarilyPublicDomain
No they won't. Copyright impossibility theorem: you can't please all of the people all of the time.