well wont be the first time he did it
he had katakuri imply luffy was on his level when he barely started seeing the future.
that was someone who still had comparable strength and combat prowess to Luffy (excluding haki) ..
after awakening semi-FS they were sharing blows evenly .. Luffy just won the battle of attrition, katakuri was still in a relatively pristine shape even after Luffy caught him off guard after kata lost his cool, until he stabbed himself to even the stakes.
Kaido on the other hand bet acoc Luffy right after zoro gave kaido a flipin scar
Luffy even had to revitalize himself while Yamato held kaido
there is no way those fights are comparable
what is comparable is the foes having to nerf themselves to even the stakes.. and even then kata did it for honor and equity while the Plot was the only thing that was nerfing Kaido for Luffy to stand a chance from scabbard to Yamato.
Look I'm in no way saying that Luffy that schmuck doesn't even stand a chance against clean pristine kaido.. i have Kaido beating Luffy at high diff to potentially extreme diff depending on how this ends
but i don't see how it's plausible to assume that luffy would definitively surpass kaido post wano