Orochi is 99.99% alive.
~Wano has been... "interesting" in terms of quality so far but Oda is not a Z tier writer lol.
~Killing Orochi here would be incredibly anticlimactic and a disservice to the arc, Orochi has far too many plot threads to be killed here, by Kaido of all people.
~Ame no Habakiri has a purpose to serve, the sword that Susano'o used to slay Yamata no Orochi in Japanese mythology, surely Oda implemented it into the story to have Yamata no Orochi be slain by it in One Piece too.
~Regardless, this completely DESTROYS the "Zoro vs Orochi" narrative. Oda has moved the goalpost. In order to free Wano, the heads of Kaido & Big Mom are the priority. Orochi is no longer a threat to the people of Wano. This is a battle between pirates that has consumed the nation, a battle between the Worst Generation + Wano Samurai vs The Yonko Alliance between Kaido and Big Mom. This is where Kaido and Big Mom are defeated, thus Oda is treating them both as central co-antagonists with an equal relevance and influence to the plot.
~Orochi on the other hand lacks the power to prove a threat to the people of Wano, however I do see him doing something impressive and having to be quelled by either one of the Scabbards or Hiyori. Whoever wields the snake-slayer, Ame no Habakiri, will slay Orochi.