They just "pushed" them out in bulk like the ones you show above. There are some sketchy Mr. Peanuts bags. If they are Alley swirls, very good likelihood of being legit. If they are older MK's with a BB or CS, same answer. If they have "Play the Game, Be Fair...." on the reverse, they are most likely legit. If they have "Play the Square...", that's where you have to look at the marbles and for the seam on the bag - that's where there may be some fakes.
Amana - Des Moines Marble Show Article (9-25-13).doc