Yes got similar communications about my Amex card.. seems to be some new guidelines.
IMO its a good thing. As you don't need to go through the headache of dealing with customer care to get any unused cards deactivated.
In my case I have tried deactivating this Amex card few times and everytime they convince me someway or the other to retain it. They even reduced my yearly fees one time
If you need to keep the card though, just make one transaction to load amazon pay wallet or something and then you are good to go for another year