I wonder the same. The Category 4 cabins have a larger interior space. These newly categorized 5E/4E will have a larger verandah but a smaller interior. Usually, the rate difference between a 4 and 5 is quite substantial as well. I think DCL may run into some problems trying to pass these cabins off as Category 4. For our family at least if we book a Cat. 4 it's for the extra interior space, I can't see myself paying more for a smaller cabin just because it has a larger balcony.