Underwater District (Dying Light 2: Stay Human)

How to drain the water in the underwater area, the developers yelled about this that if you make some kind of choice there, then a new area of ​​​​the city will appear from under the water, but alas, there is no even of this. It is not clear how to release him from under the water. The developers yelled about it as something new, but they themselves cut it out of the game?