I believe that there are two possible scenarios, the first one is that there will be a third park or major attraction as can be seen at the original statement where there was an agreement that there shall be 3 major attractions by 2020 (they pushed back the deadline to 2039 now!). Or it could just be a case of utilising the space in WDS for new attractions or lands (there is space for about 4 new attractions or 3 E tickets). I hope this solved your problem