I don't know, he could and could have not. Anywau interesting to note that Zoro as a swordsman had at first, and even now pretty much, the only target of his dream in Mihawk. There was and is nothing about Wano like "visit the land ofbthe swordsman to become stronger/ learn new techniques", Zoro didn't say anything about this, the thing that comes close he is wanting if there is the chance to learn to cut fire (but that is not a pointer for "Wano's great swordsmasters" but instead for Zoro vs King). Even Mihawk when he sent him out he didn't say anything about Wano or other places (as far as we know), but instead to look for strong individuals and challenges. This to say that even if Wano is the land of thr samurai it is not like the place of an holy pilgrimage for every swordsman, not at all. Most likely it was when Ryuma was alive so if you wanted to be the best swordsman you had to travel to Wano and challenge Ryuma not like now that you have to travel the seas and look for Mihawk.