Weird thing is I just looked at availability starting tomorrow (we are willing to switch rooms) and there is nothing available in any room category
They don't remove/add availability last second like this. Doing so would mean they'd have to scramble to re-home displaced guests and/or have a lot of unused inventory immediately following completion of every floor.
11ish months ago they removed ~1/5th the inventory from BCV for ~4 months. Because they did this before bookings, it means that the rooms were simply never booked in the first place. They're currently in the middle of their ~4 months to complete construction one floor at a time, all without last-second impact to guests.
Now that floors 4 and 5 are done they should move on to another floor when that floor has been cleared of guests, whether or not they will is the subject of "CM said" rumors above (I'm skeptical).
Despite all 5 floors being open today, they still don't have 100% occupancy available. If they intend to start moving on to floor 3 (for example), first they need to wait for all guests to clear out of that floor
then they can shut it down for construction. In the meantime there may be seemingly-open rooms, but it's really just part of the phase-out of the floor.
Said another way, this phase-out period may seem like ~80% occupancy when they 'could' have 100% until they shut down floor 3, but logistically it's easiest to just have a brief transition period rather than have spikes of 1-3 nights of availability come up last second every time a floor completes renovation.