What a strange thing.
If Oda's got sudden break, they should officially let us know by now......iirc at first, next chapter is to released on 1st Dec but they changed again..
So it seems even shonen jump can't make a solid conclusion till now.
Is it Oda personal issue that they can't speak about, it's that serious?? The suspense is pretty sus.
Hope it won't be anything to be worry about.