AFAIK the largest messdeck has 6-8 pers and there are more onsuite heads than on the current frigates. I believe that the showers will be more like the MCDV's with private booths that are not separated by male/female. Just lockable floor to ceiling, with a change area and a shower. They are building in a dedicated gym space. Don't quote me on that though. I'll ask around for more detailed information.
The outfitting and furnishing step of the build won't be known for at least two years. Those are some of the later items that get organized after the general spaces are assigned. Each space is organized by role and equipment. So a mess deck of 6 pers has to have 6 racks, 6 footlockers, 6 lockers, 1 phone, etc....
As for manning crewing max 200 crew including air det. The watch rotations stuff will likely be based on current practices but will have to be changed as the crew size is different.
There is an effort to adjust based on the new technology, information, tools and number of people for the new ships.
JSS for example will trial at some point a distributed ERT vs the current model as the ship is huge and the internal comms are better. The ship is expected a few years from now, and I'm already seeing changes to the CSE section.