How much effort would go into making it?
What would the effect be?
How would it change gameplay?
It would be similar to other content - the map doesn't serve much point after ~500 hours when you know your way everywhere (except for identifying friend locations and who has what tower). Having dark clouds covering most of it for the first hour of exploration might be a lot more effort than it would be worth?
I did not vote, as I felt the options to be limited.