Shit is going to be combined with Vegapunk/Bonney/Kuma shit too, watch lol. Vegapunk was heavily tied to Gigantification, alluded by PH, so I assume Oda needs to address the this and the Revolutionary plot as well. Then you have the final Road Poneglyph, which might be there. Then you have Urogue, who is a complete enigma. Then you have BMs unfinished storyline.
It's a lot and its painful to think about lol. Either these storylines are separate or tied together like Dressrosa did with combining plotlines.