I see, what I meant to say was that Oda's contribution in Strong World was significant enough to be considered canon, which I thought was a waste considering it could have been a decently lengthy arc between Thriller Bark and Sabaody Arc.
I heard from someone somewhere that Oda planned to make the Strong World story an arc. I dunno, I take these rumors with a lot of salt. Shiki is part of the canon story with him even showing up in the series via silhouettes; it makes you wonder just what he had planned with this otherwise minor background character.