Only in the USA.

[Ducimus]

Bird learned U.S. authorities have banned the candy because they come with a plastic toy inside that could, if eaten, choke a small child.

Well, that explains it. Our society has this odd, cultural fetish with children. Anything that puts a dent in child safety, self esteem, or might somehow shatter their virgin ears is stringently frowned upon.

(NSFW language)

So no, i'm not surprised about Kinder Eggs. (frankly, i never heard of them before).