The DRK quests referencing Darkside is actually also lore specific though, as it's also referring more to your actual 'dark side' of your soul/personality/emotions (namely,
it's physical manifestation in the form of Esteem
), which the WoL struggling to concile and have control over continues to play a major role in the DRK quests, as well as the ability of the same name, and is thus still definetely relevant.

It's one of those situations where naming an ability after a story aspect might not always be the best idea (another example is the 'Echo' effect buff not really having anything to do with the actual Echo at all, but just a cool name attached to a buff). But I digress.