i do think that the zoro-grim reaper's subplot will be addressed during zoro's next fight, as the justification of his new power-up.
at the same time, i'm pretty sure that kaido and big mom's fate will be clarified in the next chapter.
finally, i do think that kaido will come back to the story, but i also think that we'll get a sort of rocks flashback which will address several topics that kaido's flashback should have addressed.
at least i hope so, but i am pretty sure about the first two points. this ending is still too rushed