It appears that Disney World may have increased capacity for the Disney After Hours Boo Bash event. Previously sold out dates are now showing availability.
On June 15, when the tickets went for sale to the general public October 5, 12, 29 & Halloween night were completely sold out. The calendar today shows October 5, 12, & 29 as available for purchase. Halloween night is still sold out. Either Disney World increased the capacity or there is a computer glitch.
There are some theories floating around social media that Disney manipulated the ticket sales to show more popularity for the event by limiting ticket sales on release day.
The Disney After Hours Boo Bash runs on select nights August 10th – October 31st at Magic Kingdom Park with three hours of lower wait times for 20+ favorite attractions, ghostly Character Cavalcades, trick-or-treating, and performances from the Cadaver Dans.