Airbus, as I understand it, heavily lobbied both the EASA and the FAA to skip this test altogether, fearing injuries and the subsequent bad press that would inevitably come with them.
It would be an enormous accomplishment to get 800+ people safely evacuated in a real-life scenario. It's a good thing this is a controlled and sober exercize with mostly fit and focused volunteers.
Let us hope that no serious injuries occur.
I have in mind a particular Air France cabin crew that would be a great choice for the test team.
