So either they have info about an imminent alien arrival, or will have to admit that this is happening since several years ago, in at least three waves (probably), and that they knew about it.
You are making the very error that lead to UFO sightings being stigmatized in the first place.
The trick is to remember that it is like the sql NULL. No unidentified object matches any other unidentified object. It is only once you identify the object can you claim that it is of extra terrestrial origin not before. And once you identify the object it is no longer a UFO.
Or maybe the real trick is having a lot of fans hunting UFOs like "is 1980 again", while you keep the secret for yourself and build a plausible denial way out. Who knows?
The trick is to remember that it is like the sql NULL. No unidentified object matches any other unidentified object. It is only once you identify the object can you claim that it is of extra terrestrial origin not before. And once you identify the object it is no longer a UFO.