Ah I think I see. Notice the list of contents on the regular issue with the Yearbook Sticker it lists "15 picture cards - 1 sticker - 1 stick bubble gum" while the "error" only lists "15 picture cards - 1 stick bubble gum". So they distributed some packs without the Yearbook preview stickers. Maybe those were the packs sent to grocery stores and more general retail stores.
I collect: Baseball, Football, Hockey, Mostly Vintage pre1980, My Homie teams - Washington/Baltimore Teams Senators (Twins, Rangers), Expos/Nationals, Redskins, Capitals, Bullets/Wizards - HOFers - Non-sport (mostly TV shows and movies).
My Trade List is very much a work in progress
CaptKirk42s Trading Card Blog Curly W Cards Strive For '65 YouTube klandersen42