(all lb)
Folks, this is almost a nothing burger. Long EAMs happen about once a month or so and are sporadic in nature.
See evidence of this here.
https://eam-watch.s3.amazonaws.com/CSV/eams.csv
skyking and all stations are both types of messages; "all stations" is a broadcast, and "skyking" is more specific to whatever was designated as skyking at the time.
When a real event is about to happen there will be a lot of messages going out.
You want to listen to them? Go here and find a station.
http://websdr.org/