"Ability for established worlds to revert if they don't satisfy their requirements for long enough."

I take it that this means that if the "Established" modifier the planet gets finds itself ill-suited to the planet, it'll fall off and leave room for another world in the empire to become such a thing?

Edit: Well, that you plan to have such a thing occur, anyway.

That is right. I figure it should happen somewhat slowly, and only really trip if there is some sort of terrible violation.