They refered to Whitebeard by his title he earned from his prime days, but Whitebeard himself in MF stated that he cannot be the strongest forever, since his sickness was destroying him. Couldn't even fight for too long before getting a heart attack. While there was a common consenus that Kaido is the strongest in terms of combat power, at least when it comes to old sickbeard, the time which the novel covered. Primebeard > Kaido, but it's too much to ask from old sickbeard who needs to stay on his meds.
Oda himself in the SBS portrayed Kaido as the strongest.
Nope wrong,false,incorrect.
Narrator entitled box "Whitebeard, strongest man in the world"
Buggy "Whitebeard is without a doubt the strongest Pirate in the world !"
Garp "We have already angered the king of the seas"
Sengoku pre-Marineford "The world's strongest man is about to attack"
Sengoku during Marineford "Damn Whitebeard, you still have that much strength left?"
Sengoku post-Marineford "There are still many legendaries pirates around, WB was the strongest of them all"
Character bios from MF volumes "Whitebeard : the strongest Pirate in the world, he came to Marineford to rescue Ace"
Doflamingo "blablabla throne wars only happening because WB is dead and now the throne is free for all to take"
Bigmom "I would've defeated Shanks,Kaido and EVEN Whitebeard"
WB was top 1 until his death, nobody acknowledges Kaido as top 1