The program is changing right along with the indexes
I think that is the first time I have actually read that written down here (maybe it was before, but I just have not seen it). You are right. AdSense is changing. They are sending warning signs and shots, but I think people don't get the message soon, they will pay for it during a "purge". When Google does a purge in one of its services, it is not fun, but you can survive if you pay attention.