I don’t have a clue about it becoming retroactive – I doubt it, as that is not what the guests originally agreed to. However, YES, go to strict cancellation. As I posted elsewhere, it won’t help you if a guest claims they are sick even one day before their reservation (happened to me, happened to a lot of people) as Air will side with the guest, refund them all of their money, and you will get nothing – and there is nothing you can do about it. However, most guests really want to have their trip, In almost two years, that has happened to me only once. I have had guests cancel and ask if they could get a refund. What I have told them is if I can rebook any or all the cancelled dates, I will give them a refund according to how many dates I was able to rebook. I have done this a couple of times.