Silver Shamrock Masks

I’m gonna guess just an Easter egg.

My guess is that it's supposed to be a cheap reference. They were actually already in the 2018 for a scene.

It makes me wonder that since Halloween 3 and Halloween 1978 are in different universes (but Halloween 1978 exists in Halloween 3 since we see the movie being marketed/shown on TVs throughout the movie and is the movie playing during the big giveaway) that Cochran got the idea for the masks because they have their own Halloween/Michael Myers sequel in their universe that takes place between the 78 movie and the 2018 movie (maybe it's a sequel where the killer is just a copycat Michael Myers, kind of like how Friday The 13th 5 has a copycat Jason). The masks could've came from that movie and Cochran created some movie tie-in (probably why the masks are selling like crazy throughout the movie), and the 2018 movie is kind of bringing them back (for nostalgia reasons). I'm thinking Halloween 2018 would eventually exist in Halloween 3's universe/reality/world. Well, IF the final channel stopped playing the Silver Shamrock commercial and everyone lived happily ever after.

But overall, I think it's just going to be a reference to Halloween 3 and the masks aren't really that important.