This is an interesting article. I've given this topic some thought and I believe there's some merit in the idea that when Christ returns it will "appear" as if he's an extraterrestrial and that the world will unite to repel him as an invader. But I think (speculate) that the "craft" and the physical symptoms associated with them (smoke, fire, etc.) are the result of the spiritual realm manifesting in the physical realm. I do think though that the vast majority, 99% or more, of all UFO sightings are bogus. They're mistakes or have other natural explanations. I think that UFO mania is driven by Satan, who may be behind the sightings and/or abduction phenomena. His reason for doing so is prepare our mindset so that when Christ does return, we will think he is an alien that needs to be defeated.
I don't think it's 99% at all. I think it's a lot lower than that and increasingly so the last year, as usual. But I don't recall what some of the studies have shown it to be.
Way back in project Blue Book, it was 5%-15% as I recall of the top of my head--were bonafide UFO sorts of phenomena. I think those percentages have crept up year by year with the majority of GENERAL PUBLIC sightings still misperceiving conventional things as UFO's.
However, when one gets into police, military officers, commercial and military pilot reports, the percentages of authentic UFO craft being involved becomes significantly higher than the stats from the general public. Again, I don't recall specific figures.