Wipe out the infrastructure, the natives will do the rest of the nasty business for you.
So I can say that any other significant power collapse will “cause hundreds of millions of deaths”? The effects described sound pretty much to what happened in New Orleans during the hurricane. It’s hysterical hyperbole. If electricity dependant infrastructure collapses, without the possibility of rebuilding within forseeable time, folks will have to live like they did before everything was electrified.
An EMP is serious business, but this ridiculous hyperbole diminishes the seriousness of this issue.