The potential lawsuit revolves specifically around the 'Red Light, Green Light' challenge which, like the original drama, had contestants evade capture by a giant robotic doll.
This is in the UK, but in general a you cannot sign a contract that relieves the establishment of taking all reasonable safety concerns. There is an expectation of a standard and professional level of safety. The contract just gets tossed as non-binding.
However, I would be surprised if that happened in this case. I am doubtful Netflix will be found liable because I expect with the budget and visibility on the project, they had enough people involved that they took adequate and legally required precautions.