An Xfire system wide message did go out making the same announcement that was edited to Wikipedia. The cited source may have been poor but it is not an outrageous claim.
All source code is readily available on the UserScripts.org website and there's nothing destructive (other than to your existing WoW forum posts) in the code. Still, if you feel uncomfortable, you should not run it.
Although they reverted this change, I'm still pretty weary of the direction that Real ID is going. Personally, I've opted to delete all official WoW forum posts using a GreaseMonkey script I've found: http://userscripts.org/scripts/show/81103