By having more developers and writers... so the writing on the story and more is not long planned, but on the fly so it does not have to be what has already been planned.
You can't really forecast stuff like this, since it is not a single player gamer, but need to be on the fly following more what the community would like as well of course and first of all the people behind this game most of all, it would cost more to increase the staff like this, but I think it would also be a reward on its own being able to deliver even better and more spot on.
With everything, drop any of the characters voices entirely and let it be text based only, with possible an AI solution to read up if you are dyslexic, lesser investment in people needing to put voice onto the NPC's, so you can put stuff out more quick for people to enjoy, in the end an MMO is supposed to be like players in a way living in the game with other players and not so much rounded up around the faboulous 4 in a figure of speech.