Since nobody bothered to take the initiative, I got screenshots of the merch that was teased during the Live Stream.
STRANGER THINGS (shirt, hat, and "not pictured" mug)
Character IP House Shirt (Notice it doesn't feature Blumhouse characters)
^The BACK says "We Know What Scares You"
TRICK R TREAT (shirt & leggings)
SCAREZONE (11x17 poster & "not pictured" shirt)