The timing doesn't line up precisely with Revelation, but one has to wonder if these beings have been released from the "Bottomless Pit" (so to speak).
Some evidence of their appearance has been around for a very long time, but lately they are everywhere all at once.
In More Than Conquerors, Charles Hendrickson's commentary on Revelation, he sees. the two bookends of God's Judgment as the pre-flood world and history's final Judgment detailed in Revelation. In between these two are very many more lesser judgments on Babylon, ancient Egypt and so on. All of these civilizations rose and fell under the judgment of God. Thus, said Hendrickson, the events of Revelation play out over and over but in lesser ways. So this means that toward the end of a civilization God sends His angels to collect the souls of the impenitent.
In this light, apostate Western and American civilizations are under Judgment and UAPs could possibly be:
"The Son of man shall send forth his angels, and they shall gather out of his kingdom all things that offend, and them which do iniquity; …Matthew 13: 41,49