We too were subject to a rash of unpaid cancellations due to the pandemic.
But I saw it as reasonably fair. It wasn't the guest's fault. They couldn't get flights, there were severe risks in travel. It wasn't their fault. We all lose.
Nonetheless, it isn't as if host guarantee is what's written on the tin. Hardly. Airbnb is already declining damage claims at any opportunity it can find. Even when it's irrefutable and admitted by the offending guest. And if the guest refuses to compensate, there's really no penalty.
I seriously doubt that any lawsuit, whether it moves forward or not, or successful or failed, would change host support for the better.
Remember, Airbnb is a publicly held company now. Its first responsibility is to its shareholders, not its customers. Keeping customers buying is obviously critical, but consider who the buyers are. Hint: it isn't the hosts.