Having lights on is good advice, especially since you tend not to notice the evening getting darker gradually. If you've been outside since daytime, by the time you realize to turn on the lights it's already quite dark. In my country, all new cars need to be equipped with daytime lights and even before that rule, using lights at all hours has been mandatory.
However, this advice is a bit questionable:
"Flashing LEDs (front and rear) are especially effective for cyclists as they create contrast and the on-off flashing attracts the peripheral vision in the same manner that movement does."
Flashing LEDs as your only light is really bad, because it's impossible to judge distance and speed from a flashing light in darkness.
Having a flashing light on your helmet or handlebars in addition to a normal light may be beneficial but only if you have otherwise decent lighting on your bike.
In fact, in my country there are regulations that require a non-blinking white light on the front, a non-blinking red light on the back and reflectors on the pedals and wheels. There are actually quite strict rules where and how the lights should be placed.
Unfortunately not everyone complies with these regulations, and the worst offenders I see are children. I've seen kids riding bikes dangerously on the roads (and had closer calls than I'd like to) on otherwise affluent neighborhoods. Their parents (and themselves!) had completely neglected to put lights on their bikes (or check that they work, have batteries, etc).