I think his devil fruit will trigger some sort of special hydra abillity and he will be back, could be that even Orochi himself didnt know that his fruit have this special ability.
Probably his plotline will go into Hiyori direction, Oda chose to show us that Orochi knew where she is and even have established some connection between the characters with the Komurasaki thing. I think he will somehow be able to capture her and in the end Momo and Hiyori, as the representatives of the Kozuki, will be ones to end this Kozuki x Kurozumi plot.
Luffy and the pirates are here to deal with Kaido and his pirates, the plot of the internal problems of Wano is a thing for the Kozuki to deal with.