Hi,
As others have noted on newer ships accommodation requirements are changing. Specifically (if I am recalling correctly) on the USN's Littoral Combat Ship (LCS) and USCG's National Security Cutter (NSC) the original plans (at least) were an accommodation requirements termed 1-2-4, where senior officers were to be accommodated in single person staterooms, junior officers in 2-person staterooms, and all other in 4 person staterooms, although I believe that in practice some variation actually occurred (with some 6-person staterooms etc).
I believe that such accommodations were proposed as a means of trying to help in the retention of the highly skilled technicians that newer and newer vessels are beginning to require, as having to train new crew members all the time (as service members put in their service time then retire) is a drain on service resources. As such, it wouldn't at all surprise me that in the future, an even greater space allowance might exist.