I'm hoping out on a limb here and I hope I'm wrong but after watching "Makkng of an Icon 3" I can't help but feel that the Hideaway will be a for a fee venue. In the video they referred to it as similar to the Beach Club which is also for a fee.
It looks to be small, exclusive and have easily gontrolled access points and some unique experiences that would certainly lend itself to being a for a fee venue. Another first at sea.