I was curious to know how difficult it would be to be able to show a series (and possibly a universe) as completed or in progress. Recently I started reading a series that had 2 books in it. Both individual books were completed and hadn't been updated in several years. In fact, the last time the author posted anything it was a blog in 2018. I read the first two books and it was only AFTER I finished the second book that I realized there was supposed to be one more book but the author never finished it. I had no way of knowing that the series itself wasn't finished. Would I have still read the series if I had known? Maybe, I honestly don't know, but knowing ahead of time that a series is incomplete would be helpful.
You could POSSIBLY do the same thing for universes, but that gets much more complicated since a universe could be written by multiple authors (i.e. Swarm).
I know there are lots of readers that don't like to read a book until it's finished, and likewise with a series.