No, the Ace novel implies that one of Ace's crewmates thought Kaido > WB. That is his perception. The manga states otherwise. Oldbeard was still the strongest man.
Similar to how the Databook Vivre Card confirmed Mihawk's title and said that he's the strongest swordsman by title and actuality, the Ace Novel "half-confirmed" (since it wasnt stated directly but said by persons its not a real confirmation, but we can take it seriously) Whitebeard's and Kaido's titles - saying that Whitebeard is
1) the worlds strongest human alive
2) the strongest pirate (in terms of piracy)
and that Kaido is
3) the strongest creature alive and even stronger than Whitebeard.
In the Manga it was always stated and implied that Whitebeard is the strongest man alive and the strongest Pirate (where we now know thanks to the Ace Novel that it means "in terms of piracy"), but never that he is the strongest character. I mean Kaido is non human.
So Pre TS: Kaido > Oldbeard > everyone else (I guess Post TS things changed, like Sakazuki beeing = to Kaido)