JTO,
Perhaps I can help here.
There's always been a challenge in locating large spaces on a carrier - which is always a crowded ship, no matter how big. The QEC class is unusual (for a UK carrier) in that it has a continuous deck located one level below the flight deck, and above the hangar. (This has been called a 'gallery deck'.) This generates a lot of additional compartments, and also a space that is tailor made for the very large 'arresting engines' required for cat and trap. As the QEC design was required to provide a structural space for this kit, large compartments were therefore designed into this 'gallery deck'.
Early on in the F-35 programme, it became clear that the mission planning task for this data intensive aircraft was going to require spaces that were not only large, but also able to handle very classified information. There were also pressures to locate the spaces higher up in the ship to provide short routes for the physical transfer of data from MP areas to the aircraft, and (not incidentally) shorter distances for the aircrew to get to and from their aircraft.
Using the large arresting gear structural spaces for the mission planning suites was an obvious and (in my view) sensible solution.
Lots of people will work on this gallery deck, some will even sleep on it. (Much like most carriers). Yes, there will be some noise, but there will also be hell of a lot of soundproofing and insulation. All part of that seagoing stuff.
Hope this helps, best regards as ever to all those working on board, on whatever decks,
Engines