Nooo. 1914 + 3½ years isn't meant to add up to 1919.
It's meant to add up to the year of Jesus' inspection - 1918. BUT:
"Some of the brothers living today did indeed pass through a time, during 1914-1918, when Jehovah was displeased and did allow his organization to undergo captivity to Babylon the Great." - w69 6/15 p. 378 par. 44.
"Under the direction of this religious corporation the great world-wide campaign to announce the 1914 end of the "times of the nations" was undertaken, as mentioned earlier. The Watch Tower witnesses of Jehovah proved to be awake spiritual watchmen. But the Scriptures describe them as having unclean garments because of their long association with Christian apostasy. (Zech. 3:3, 4) They had many practices, characteristics and beliefs similar to the weedlike sects of Christendom. So from 1914 to 1918 a period of fiery testing came upon them, not unlike the ancient period of Babylonish captivity of the Jews back in 607-537 B.C. ...
... As we now know, this watchman class of the "faithful and discreet slave" was being cleansed for still greater watchman service in the turbulent years to follow their restoration in 1919. Previously, in the spring of 1918, Jehovah came to his temple of earthly Christian servants for inspection and cleansing. (Mal. 3:1-3) The many bad ones were disfellowshiped by Him and sent away. A loyal remnant were permitted to go through the fiery test where Jehovah and his Messenger, Christ Jesus, (1) tested them by organization arrangements on their loyalty to Jehovah's organization rather than to human leaders, (2) tested them by service instructions and provisions as to their zeal and devotion to Jehovah's worship and witness work, and (3) tested them by revealed truth as to their love of it. What a fiery time it was!-See You May Survive Armageddon into God's New World, pp. 303 to 305.
A faithful remnant of some thousands of the "domestics" of the "faithful and discreet slave" class survived this time of testing. From the spring of 1919 forward they began to rise from the dust of inactivity to their new lofty service as watchmen to the world. (Dan. 12:2; Rev. 11:11, 12) The Scriptures also describe them as being clothed with new garments of clean identification to represent Jehovah's interests in the earth.-Zech. 3:4, 5; see the book Preparation, pp. 55 to 58." - w60 7/15 pp. 435-436 par. 18, The Awake "Faithful and Discreet Slave".
So the WTS and BSs were inspected, found wanting, punished, then 'appointed over all Christ's belongings' anyway LOL.
And to get from 1914 to 1919, there's some jiggery-pokery involved with Revelation's and Daniel's 1260 or 1290 days, the killing and revival of the 'two witnesses' and Ezekiel's valley of dry bones and other such interpretative nonsense.