The Arizona was in fact decommissioned.
http://www.nvr.navy.mil/nvrships/details/BB39.htm I bought off on this myth for a while myself until someone brought it to my attention that she was decomm'd, and rather shortly after PH happened. As for looking for the Okie, you're looking for a needle in, well, the ocean. My guess would be no one has funded, or wanted to fund a search for the wreck.