If you actually read the article, seizing eggs at the border is an attempt to curb the spread of bird flue. It's decently common to make moving certain foods across borders illegal due to disease concerns
You've never been allowed to bring raw eggs of any kind across the border. I'm sure you can declare to do so and make arrangements for it, but I can't show up at the border and bring eggs over, that's always been the case.
I suppose you are right, in that it's not the egg that's illegal, but the action of bringing it over the border.