Yeah, the merch in the land is "in universe." The merch outside the land (outside of some stuff apparently "smuggled out" to Launch Bay) is out of universe. So most things that actually SAY Black Spire, or anything that says Galaxy's Edge, or what people are likely most freaking out about, merchandise dated to May 31st 2019/Opening day - all that will be outside of the land itself.
I've got the 8-12 noon reservation slot on the 31st, and I can't be in two places at once, if there happens to be an opening day pin left when I get kicked out of GE itself, happy day. If not, well at least I got to see the land itself right?