applegaa PM'ed me the story link. It's on literotica. And I do see the same issue.
After collecting the chapters list, adapter_literotica explicitly sorts them by date. Git blame shows that line was added with some other changes as
Updates to adapter_literotica from davidfor.
At the same time, datePublished and dateUpdated, started being populated from the chapter list instead of a separate dates list, but the code for the dates list was not removed, just overridden. That suggests the change was incomplete or perhaps just hurried.
So it's possible it's just a mistake.
MR discussion at the time doesn't say anything either way.
But it also wouldn't surprise me if it was included to address authors accidentally putting their chapters out of order. Does anyone have any examples of that?
I'm inclined to just remove the chapter sort, but I could make it an optional feature instead.