I think he might have given up on it and is using OP to compensate for it? Hence the Vinsmokes, Franky post TS, Queen and MADSs and such? Also the emphasis on space especially with Enel's cover page story? Might just pulling at straws (or straw hats even) here though lol.
Araki is still drawing Jojo after 34 years so Oda might still do another manga LOL! (Or OP will still be going for that long LMFAO!) Seriously though, I'm hoping he takes a massive break after OP is finally over and if he wants to do another series, to do a short, monthly series, nothing more extreme than that.