The article mentioned a few negative consequences that would occur, but left out the elephant in the living room. The absolute worst "inconvenient truth" about an EMP event (whether from a hostile attack or natural source, such as the sun) is that it is able to take out command and control in the nuclear power plants in its affected region, in addition to the grid.
This means that the cooling systems will fail and the reactors will melt down. Imagine Fukushima multiplied by N (insert 1 <= N <= 61 for the US). Fukushima had multiple safety mechanisms that all failed. A widespread EMP event is orders of magnitude worse than a nuclear attack on an individual city.
Dr. Peter Vincent Pry reminds us that when the power goes out.....within a month after batteries deplete, the cores of our nuke power plants will overheat from lack of water "powered" to keep the rods cooled. And then we have "nuclear" fallout spreading across the country.
Pry is executive director of the Task Force on National and Homeland Security and director of the U.S. Nuclear Strategy Forum, both congressional advisory boards. He also served on the congressionally mandated EMP commission and as an analyst with the Central Intelligence Agency.