I have never seen a single article that said a high GI is necessary for anything healthy, except maybe runners and bikers who carbo load before events.
For everyday people, and everyday living, low GI foods are much better for your energy levels, mental agility, etc. The egg breakfast mentioned in that article included toast and jam, which raises the GI levels. I often eat 2 eggs with yogurt or fruit as my breakfast, and it keeps the GI levels low, without too much protein. (I am hypoglycemic so I have to keep carbs to a minimum).
High carbs for any meal, except maybe dinner if you're not planning to be active afterward, is a sure way to make yourself sleepy. Before I knew I was hypoglycemic, I would eat pasta for lunch quite a bit, but be sluggish and practically falling asleep at my desk the rest of the day. If I ate tuna instead, I was on task, mentally alert, and highly productive. Then I found out why and changed my diet permanently.
Thanks for posting the article!