Yeah, this tracks. It's usually just a matter of time until either a divine/demonic entity appears, or a fracture between the world occurs, or some sort of cyclical system between worlds go awry and then we get fantasy invading the "real world". Now we either have them remain covert or it becomes something that breaks containment and whatever SCP type organization that may or may not exist is unable to stop it from being known to the populace.
Though based on the premise at the start, I'm guessing it's going to mostly remain covert.