On October 1, 2020 Extenuating Circumstances COVID policy has updated to a 45 day rolling basis now.

Reservations for stays and Airbnb Experiences made on or before March 14, 2020, with a check-in date within the next 45 days from today, are covered by the policy and may be canceled before check-in.  https://www.airbnb.com/help/article/2701/extenuating-circumstances-policy-and-the-coronavirus-covid19