I think that means that, even if someone like Muzan or Tamayo - who have created new demons - dies, then the demons they create still live. Honestly, I was just blown away by Yushiro's last-minute attack! I didn't think we'd see much more of him!ヾ(☆▽☆)
Which is good because if that was the case, it means that if Muzan dies, Nezuko mught die too and people are gonna riot if that happens ╮(￣▽￣)╭
Must be because Tamayo's method of creating Yushiro is different from Muzan.
Spoilers for those who haven't read chap 180 and up...
.......
.......
Why didn't Yushiro die when Tamayo died? Not complaining that he's alive though...Let Hawt Muzan burn!
╮(￣▽￣)╭