Or just prohibit the host from offering it to new guest when they cancel. If I rent a place for a week and they cancel on me the day before, don't allow another rental through Airnbnb for that week.
Airbnb isn’t the only platform, so it’s unclear that even if Airbnb started trying to do this (which they likely wouldn’t, hosts are their source if income) that the host wouldn’t rebook on VRBO, Homeaway, etc.
I think this is actually the majority of the cancels. A host lists their unit on a bunch of different platforms (sometimes the same platform) with different costs and cancels all but the most expensive one last minute.