Really the question is what comes after. Is this done or is this not done? I don't expect the punch itself to take long, it doesn't make sense to stall it because Luffy was falling back down to Kaido mid air last chapter (the fist came out of the clouds and Luffy is falling in that close up to his face:
The punch itself is a fitting final attack, but the context surrounding it feels lacking to actually be the ending of the fight.
-Orochi's plot conclusion,
-Momo finally being able to produce flames clouds.
-The Flower Capital folk getting to finally see what's going on.
All of these feel necessary for a final attack really feeling conclusive, and this isn't even considering a potential Kaido flashback, which could happen after his defeat.