This is 30 years ago, but my sophomore year my roommate transferred out and a freshman moved in. I think had it been at the beginning of the year, it would have been fine. It was awkward though. Not bc she was a freshman but bc her boyfriend never left our room.
You can keep your diagnosis to yourself. My S usually does. People often find him odd. But he also very funny, so they just scratch their heads and ignore his oddness. Once in a great while it causes a problem. We let one of his friends know it’s happening and they usually know what to do to make it stop or redirect it. We got busted on this once though and S was mad…
Now in your case, the issue isn’t that you are a junior and they are sophomores. It is that you don’t know them. Do they all know each other or all you all random to one another?