Luffy will appear to be Dying, i think that's the Tragedy of Act 3
Because if Oda didn't kill Scabbards, then who is more important than them in this Arc?
Luffy always faced death against his previous Foes & got saved by friends & allies, since this time they are against 2 Yonko & the stakes are very high then imo Luffy's temporary loss should be worse than Crocodile stabbing/dehydrating him or Magellan poisoning him
Thus i believe Luffy will be severely damaged by Kaido, BM will take some of his Lifespan & in addition with how far he pushed his Body before (Such as MF & Impel Down & Enies Lobby ... etc), Luffy will be on the brink of absolute death, and it will be time for Law to finally use Eternal Youth Operation & save his Life & entrust him with his Dream of finding meaning of D. (Something that Luffy never got interested in, but thanks to this Scene & Law's Sacrifice, he will)