The ghouls and supermutants and special mutants like Harold would die I presume.
And the mutated people who lived topside.
But what about you?
You could be half pure dna because going by some things James might have come from a vault in New Vegas.
But Catherine could have come from the Wasteland.
So you are half or all mutated at least.
Do you die?
What about the mutated animals?
Does the modified F.E.V affect only people?
If the mutated animals died, what would they eat or hunt?
It is a plot by a insane supercomputer, but still.
So what happens?
In Broken Steel does a lot of people die or disapear?