Loaded statements.

Whether I book the room I want (which I do), whether Hyatt is fairly marketing the benefits, and whether Hyatt is being "generous" are three completely separate questions.

Upgrades are not guaranteed in the sense that availability may very well run out at check-in, but Hyatt does not like to advertise their definition of "available" as well as they advertise about Globalist benefits, in order to increase loyalty and business. If they advertised the benefit as "whatever the property feels like, including nothing, even when rooms are wide open", I'd suspect a lot less loyalty and business as a result.