This no-advance-notice devaluation of the award chart is a very customer-unfriendly move, and yet there is barely a whimper about it.
If this no-notice devaluation approach is the new way Hyatt deals with GoldPassport customers, and if customers just accept it without much issue, then this won't be the last time they hit customers this way. Welcome in the future consequences of apathy, if you're fine with this just because.