Watchtower 2000, January 1st, pg.8, par.10
"True to Bible prophecy, this world’s “conclusion” began in 1914 and was marked by the outbreak of the first world war. (Matthew 24:3, 7) There is strong evidence that Satan and his demonic hordes were cast out of heaven following that year."
"Strong evidence?" Notice the word "strong," which is an adjective to describe the evidence. If it were strong why do only Jehovah's Witnesses believe this?
If I said that I found strong evidence of intelligent alien life that had come to Earth what type of evidence would you expect that I had found? Video or photographic evidence? DNA or tissue samples? Alien technology? Alien alloys from space craft?
I think the whole conversation is just an exercise in the Watchtower moving the goal posts again to support their conspiracy theory. It's all speculation and conjecture. There is no evidence.