He might done in the sense that he's done with this shit and has had enough lmao.
This is way too anticlimatic for it to be over just like that. No witnesses, no victory declaration and thus message by the narrator or w/e too.
I feel Oda is baiting us as usual but maybe he's trying to move the plot on finally and actually get us out of Wano. Kaido's birthday was 11 days ago and the 1st of this month which is not a good sign though. Someone said OP villlains tend to get beaten during their birth days/months and Jack was beaten on his actual birthday too...
The fact he's done this just before a break is especially sadistic too.
But I refuse to believe Kaido is done, not yet. This is just too underwhelming.