The general consensus is they are limiting availability. Why, I'm not exactly sure?
Some thoughts:
A trusted insider elsewhere speculated that they can avoid discounting inventory and keep costs low because they are shuttering floors, buildings, etc. Limiting occupancy (or at least the optics) is a better look for the stakeholders. It gives the illusion that the rooms they are making available are all booked. That is true...
I also sort of think: the demand is not there like they originally thought. And Disney knows it...Covid, Delta, rising costs, international travel, employment concerns -don't look past the chip shortage-, etc. - it all adds up as deterrents. Yes, the 50th is a draw, but most revenge travel has already been satisfied (especially by WDW enthusiasts).
Now does it make sense for travelers to go this holiday season or try to wait one more year when we all kind of expect the world to be more pre-pandemic (aka normal). +Tron, +GotG, plus old favorites like Meet & Greets, character meals and the Disney Dining Plan?
(That's why I built the Disney Comeback Index - this all relevant to its purpose)
I believe the crowds will be extremely heavy for Oct 1 and a handful days after. Then it will mostly level off except the holidays.