Delaryn needs to be part of the story

https://www.gamereactor.eu/wow-shadowlands-chains-of-domination-preview-and-interview/ It’s pretty openly stated in here, and that’s why I think that the Jailer will be used as a scapegoat to absolve Sylvanas of her crimes, just like Sylvanas was used as a scapegoat for the Horde and Saurfang.

In the grand scheme, but not in relation to the Night Elves. Sylvanas did more bad to them than the Jailer, the jailer without Sylvanas couldn’t have done anything to them.
That does not mean that the Jailer is not to blame at all, but it also doesn’t mean that Sylvanas should be able to say that “the jailer made me do it” in some crappy twist.