WB was still stronger given his title of world's strongest man was never questioned and I doubt Kaido improved in those two years. Still, Newgate's health is a questionable factor that could turn things in Kaido's favour. I'd still go with Whitebeard winning, since even though his health cost him several missed opportunities at Marineford, he was constantly fighting Admirals and the like as well as having allowed Squard to stab him, far different from a 1 V 1 situation.