he would probably do everything in his power to make it seem like it won't happen and then bam so for me yes its 100 percent confirmed to happen it makes to much narrative sense l
Oda isn't playing 4d chess to game the readers. One Piece subverts expectations occasionally, but the story is also very simplistic. Most of the fanbase expects Luffy to beat kaido.
ZKK is like Arya killing the Night King in game of thrones.
It would subvert expectations too much and alienate a large portion of the fanbase, which is why its a crack theory.