@Bill1342 A relevant paragraph:
Subject to the policy’s terms, insurance coverage under the HLI program provides Hosts with primary liability insurance while hosting guests. The Host has the option to make a claim first under the HLI program instead of their own insurance policy as long as the Host’s own insurance policy allows them to do so. Hosts or their insurance advisers should check the terms and conditions of their own insurance policy.
The Airbnb submission form asks if there is other insurance coverage. Seems to me that Airbnb will then expect to be secondary, at least here in the US. Personally, I have always protected myself with insurance that I have obtained in my name for my property.