So I watched the ending of Demon Slayer: Hidden Village arc and while it was awesome Nezuko is no longer harmed by sunlight, my concern is... doesn't Muzan now know the location of the hidden village? Isn't their secrecy was to assure demons can't stop the Slayers corp. supply of weapons against demons? No Swordsmith Village means no special swords.
Two of the Upper-Ranks found the village so it's likely they informed Muzna of its location. Muzan would just send a horde of lesser demons to the village until it's wiped out or something.