I think I would summarize it somewhat differently, that God is (as a constant state of being) willing to destroy the world with a flood whenever it is as it was in Noah's time (which criteria determine this are not necessarily known to us, except insofar as they were met then and are not met now).

So from our/Noah's perspective, that situation has come and gone, has changed, because we're bound by physics and the passage of time and cannot exist in that circumstance any longer. But from God's perspective, that world is always destroyed by flood. It may be the case that the criteria that categorize a world as "destroyable by flood" never exist in our experience of time again, and it may equally be the case that God knows this will be the case.

But God's willingness to destroy the world by flood under those criteria has not and will never change, because God's will does not change.