I just found the Domo Governance connector, and loaded the tables.
The table "Data Flow Details" has a field called "Hydration State", and it's populated everything as 'dehydrated'.
Anyone know the meaning? What are my dataflows thirsty for???
So from what I was told, Hydration is no longer used for Dataflows. It was just a fancy way of telling if the input datasets were ready to be used.