I actually ran the SciTech division overseeing the Tesseract research in my agency for the first two years it was malfunctioning before I was reassigned and then largely decomissioned.
But basically. Infinite worlds theory, right?
For all we know, every single of us could be from unique universes that may only be minimally distinguishable by something like the non-existence of waffles. Or waffles and pancakes are swapped. Or they may be similar up until a point of divergence, say, the Battle of Yavin or something, where the timeline just takes a different path. New teams are there that weren't in other timelines. Old teams that are in the other universes aren't. People wind up dead or on different sides where they lived before, and that kind of expands as you have more time from it.
In my world, the most of people who came through the Tesseract were popularly recognized as characters in television, books, movies, that sort of thing. Star Wars--the timeline you guys are from was movies then comics, books, tv series, etc in my world. Some were alternate versions of people we had in our world, like say, Tony Stark and occasionally we'd have refugees "recognize" us as comic book or film characters in pretty prescient ways.
The difference was somewhat left up to others from that universe cluster to classify based on shared or differing experiences, or some "netflix" versus "book" distinction on our end. If that makes sense? Sort of a modal (or fictional) realism.
I don't know if that's a perception that exists here or that multi-dimensional perception was limited to our universe. But they were definitely real people who came through the Tesseract, some of whom had pretty keen insights into our world too.
I will say specifically to your universe cluster, while I grew up watching the films, and definitely picked up some from observing and working with our refugees, I'm not entirely well versed in the nuanced differences, particularly outside the Solo/Skywalker clan and I mostly knew them through Mara.
I don't think the Tesseract's strictly relevant here, we actually had a pretty good team kind of get it in hand fairly recently--I say as I'm in the wrong timeline. But, what do they know about how people show up here? Other than just, kind of showing up here and getting texts saying to check into a strange hotel?