What most people fail to realize is the fact that its not a "core part", Its just extra. Think of it as a story from a comic book / videogame that happens between episodes from the original SW trilogy, but are not even mentioned in the movies.
The story of the chapter itself gives a finale to the Shroud quest series from 2.0, a series that is pure optional, hence if you havent done that, this bonus chapter doesnt make much sense.