What happens to books that are submitted that no longer are legal for whatever reason? We have had the training change on the Wizard, and certain spells have become more limited in number in terms of legal quantities in the books in the past... so it is possible that similar changes may happen again.
Also, should spells be changed, certain spellbooks may become less powerful. Wizard's Tower comes to mind as one example. Should spellbooks that win championships that lead to revisions be maintained on the list?