Well no wonder his teacher is portrayed to be having Adv CoO based on Databook, and zoro is destined to surpass every swordsman including Fujitora, Fujitora has literally one of if not the best CoO feats in the series, so it's not far fetched to say not only does EoS zoro will have crazy CoA, he will also most likely have crazy CoO
Also, back in Dressrosa, it is said that Fairies have been in disguised for years, and apparently zoro was probably among the few that could notice their presence. Not even Sanji and Luffy could notice their presence
see middle right, Sanji was even mistook Fujitora as the thief, he didnt know if it was all due to fairies. Meanwhile zoro:
as shown, Zoro could sense her fairly easily