There will be soft openings, likely very soft, a limited number of people, much like was done in IOA.
You have to open, try out traffic flows, have employees cook, perform, and work in their stores before they get slammed on 1 day.
Employees get the majority of soft trials, I got to experience spiderman way before the ride opened. And rides will cycle for hundreds of hours before they open. Thus if an employee gets stuck on a ride, no harm, if 30 tourist do, WFTV has the helicopter over the park.
Walls will likely get pulled back closer to opening, but stay in the portals for access control.