Arabasta Zoro wasn't authomatically able to cut everything simply because he awakened the breath of things or, as it is apparently called now, advanced armament. He could barely dent Kuma's body, his inability to cut diamond was hinted through Bonez, he arguably still can't cut fire or at least couldn't in Punk Hazard, he required an improved version of Shishi Sonson to slash the dragon... The notion of the strongest sword being that which can cut anything but nothing at the same time is already quite a direct statement about how mastering this power is a matter of developing your learning and not simply a black or white thing.
Again, I'm repeating myself for those who know my take on this issue, but if Oda wants to remain consistent on his retconning of the breath of things Zoro shouldn't require strength to cut Kaido but hearing the breath of his scales and connecting his will to them through his sword. And this require at least some process of learning.