Well i think they will now bring the kids on the ship,but they wont sail immediately.
I think now something will happen that will block the Holy Knights from leaving:
-Luffy's intervention: the most obvious for everyone
-The Heaven World: this can be a wild card because we dont know whats there. New enemies? New allies?
-Shamrock's return: maybe he will comunicate new orders so their mission wont be over yet
Going to Marejois would be cool,not only for the similarities with Enies Lobby and Marineford,two of the best arcs,but also because i believe Blackbeard is going there too. So if Oda would want to finish One Piece earlier than some people expect,he could make that plot choice,and make Luffy, Blackbeard,Imu and Akainu all meet in Marejois in an epic final battle (with the Revs showing up too mid-arc) but i dont think that will happen. We will get this Elbaph arc and then,maybe the final war will start,or maybe we will go to Laugh Tale first,and then the final war,we'll see. But first we have the Elbaph arc for some other time yet.