I understand that fellow hosts want to explain the policy and stick to the facts and I appreciate the input @Mike1034
From a policy standpoint you and @Anonymous are missing one difference between a lease agreement and an AirBnB agreement. Guests have to request a change in reservation and hosts have to agree to that change. If those two things don't happen, the guest must have a compelling reason.
Per AirBnB, long term guests can't announce an early departure and expect a refund. If the guests wants to depart early and if the host agrees to alter the reservation. At which time the two can mutually agree upon the departure and refund decisions.
Even so, my larger point is that AirBnB has changed in the last seven years. And I think it's not a good business partnership when -
one partner can't speak to the same person about the same on-going case
one partner is told six times that AirBnB agrees with them only to have it overruled without notice
one partner asked to continue the conversation with someone more senior only to be told "no"
I could go on but you get my point.
My post isn't about their policy. It's about their lack of communication and customer service. Policies don't betray you...business partners do.