i think that this thought is really interesting.
my quick research ( and i'll dig a bit better when i have more time ) shows that wt articals after 1995 a bit vague when talking about ww1.
but here are some interesting quotes;
"What of this new creation in modern times? In the year 1914, as the Bible timetable shows, the words of Revelation 11:15 were fulfilled: “The kingdom of the world did become the kingdom of our Lord [Jehovah] and of his Christ, and he will rule as king forever and ever.” The first act of Christ as newly installed King was to hurl Satan and his demonic angels out of heaven down to earth’s vicinity. This brought “woe for the earth,” in the form of the first world war and its attendant distresses.—Revelation 12:9, 12, 17". - WT '93 1/1 p.6
"If that is the case, though, why did World War I break out in 1914? And why has our century seen worse wars than any other in history? Because the first act of the heavenly King was to banish Satan for all time from the heavens and cast him down to earth’s vicinity. The result? The prophecy says: “Woe for the earth and for the sea, because the Devil has come down to you, having great anger, knowing he has a short period of time.” (Revelation 12:7-12) The great wars of our century are related to the anger of Satan. But notice: Satan’s anger is for “a short period of time.” The crisis will soon be over!" - WT '90 4/1 p.8