I’m not following. Why would the shows being closed lead to the reservations going quickly?
Surely the reasons for the park being booked up fast is the small capacity plus the fact it has the three newest rides - Rise, Millennium Falcon and the Runaway Train.
Of course that is a part of it, that and the other two parks are not open for those days that booked fastest so people starting their trips also have only two parks to go to.
The other factor is more venues open equal a larger capacity. If you offer less space, the 30 percent (or whatever percentage they are reducing it to) is much smaller.
You want a cup half full of water, if the cup is larger(more space for it to go) there will be more water (or money spending) people allowed in.
Half of a gallon is more than half of a quart.