User blog comment:Miskos3/Fairy Tail 538: When the Flame Goes Out, Review/@comment-4933386-20170602135510/@comment-4933386-20170602135653

My other theory is that the world is getting rid of magic, just like in Edolas, but because the "10%" of the world are actual mage, they'd die too.

So this brings back to the Ultimate Magic world that grimore Heart was trying to achieve, but this one is the opposite, where only the non-magic users survived.