So... even if the author had finished it here I don't doubt some people would complain that Nezuko wasn't used in the end, so... what about you guys wait to really see the end BEFORE you complain about the author's intentions?
Before someone says that the author intentions are predictable, yes they really are predictable, didn't say they arent but since the beginning, this wasn't a groundbreaking story this has a very linear very simple and common story but it has its moments and we waited until here I think we can wait a little more to see how it is handled.
Just spitballing, I know my idea is crazy and without sense.