I find the couching the discussion only in terms of DLC is limiting. The truth is this content was part of the bonus content from Collector's Edition. Instead of giving those consumers useless items or a physical statue Bioware gave those people a meaningful piece of content.
With movies they release the theatrical version of a movie then usually six months later they will put out the Unrated/Director's version of the movie. The only thing Bioware did was to put out both versions of this model at the same time with an upgrade path for people who bought the theatrical version.