I did read it and don’t know if it would be the end of the world. I did note that they however pointed out several times that they were relying on unclassified information so there seems to be much we don’t know, I think it is an issue that should cause some concern though.
Really if we’re getting nuked EMP is going to be in the collateral damage zone. Certainly it will add to the level of suck, but it’s not going to be a handful of nukes kicking the country into the 19th century, it’ll be more in the “and top of everything else most of Connecticut is without power”. There are just really no good indications that it’s a serious threat, especially as a primary attack. One of the things people forget on this is that altitude miles are, from a practical perspective, a lot longer than horizontal miles. They talk about detonation altitude of 400KM (about 250 miles), well that’s where the ISS is, not exactly a like altitude for a device.