Something that just popped into my head and, hey, I've heard crazier but
What if
Let's say the first couple of days, maybe even a weeks worth WDW decides to invite, for free, CM and their families to experience "some magic"
CM would have to sign up on the HUB, giving Disney complete control over amount of people, working cast can implement and practice whatever new measures will be in place.
Obviously Disney will lose money doing but it would give the world an idea of what they are doing as cm and families will be able to take pics/ record/ live stream. It will give working cm the opportunity to practice, and cm families would have agreed to go in and be "guinea pigs" so no potential of backfire
Just spitballing here