I would use the same argument regarding page histories, they are probably not under the GFDL as these are retired files, why would one want someone to cite an out of date version of an article when a new one might be available? It does not say they are released under the GFDL on the page, so they may be covered by regular copyright law.
Alex756
Sometimes articles deteriorate badly under the influence of tendititious users. Occassionally a better article is in the history and is cited by others.
Fred