Because stormlight is sparse, Kaladin and his closest bridge 4 buddies (minus teft perhaps, who will sub in as head of the guard) will travel to hearthstone on foot/horse/boat. The journey will take up parts 1 and 2 of the book and will explore Roshar further. Perhaps the Horneater peaks?
The crew of the Wind's Pleasure will be back and may transport Kaladin to Hearthstone or Shalan somewhere.
Oathbringer turns out to be the name of a book, just like the previous two SA titles. The book is either a history of the sword or of the person or thing that the sword was named after.
Helaran reappears, at least in passing, but is not reunited with Shalan.
Kaladin's next oath, should it be spoken this book, will be to trust the counsel of those he leads, and the result will be that they gain/increase the capacity to surgebind as squires
Moash gets a few more chapters as pov, at least in interludes. He rises in the ranks of the Diagram and is seduced by the doctrines at first but eventually flees to warn bridge 4, hoping to redeem himself.
Kaladin teaches Elokar to be a leader. Elokar changes all our minds about him. Dalinar starts to feel threatened and realizes he doesn't actually want to yield power back to Elokar, competent or not.