That is stupid.
Also stupid is running fiber optics out to rural areas where no one lives.
You could subsidize satellite Internet for far cheaper and more effectively reach your goal.
Also flawed in your premise is that people would evacuate if the sirens went off. Most people wouldn't, just look at how many people stay behind during hurricanes with days of warning.
We both know that you are trying to make this into a political issue for partisan reasons. It's a natural disaster, a once in millennia event. Earthquakes, flash floods, wild fires, mud slides; these things happen on planet earth.