To follow up on this - After 2.5 days, I was finally contacted by a support person from AirBnB. They asked me to provide official goverment links to COVID quarantine requirements. Once I did this they said they were going to give me a one-time courtesy waiver and re-open my calendar. I continued to have a long dialoge with them about how this shouldn't have even been an option and how AirBnB should have something in place to prevent this from happening. So if it happens again, I've used up my one-time courtsey? The support persons suggestion was that if I get another booking outside the quarantine area, that I use the option that I am not comfortable with this guest and then contact them. I've seen this option, but never used it so I don't know what the ramifications would be (in any?) in using it.