The WTS gives them an out regarding their understanding prophecy right here: Current statements in 2020:
April 2020 WT Study magazine, p. 2
As those Bible students soon found out, however, it can be one thing to learn what the Bible teaches about a certain doctrinal subject but quite another to discern correctly the meaning of a Bible prophecy. Why is that so? For one thing, Bible prophecies are often best understood when they are undergoing fulfillment or after they have been fulfilled.
** w11 12/1 p. 12 Who Can Interpret Prophecy? ***
“Interpretations belong to God” also in that he determines and directs when a prophecy is to be understood by his faithful servants on earth. The meaning of a prophecy can be discerned before, during, or after its fulfillment. Since God tied up the prophecies, he will unravel them at the right time—his time.
Or this: *** w11 12/1 p. 12 Who Can Interpret Prophecy? ***
The inspired prophets of old, such as Daniel, did not personally analyze the current trends of their time and then attempt to unravel a complicated future by uttering a prophecy. If they had tried to force the future to unfold in this way, such prophesying would have originated in their own imagination. It would then have been a human prediction, a forecast built upon an imperfect foundation.
Or this: w04 2/1 p. 21 par. 13 "The Scene of This World Is Changing" ***
Since Bible prophecies are often fully understood only after they are fulfilled or are in the process of fulfillment,we will have to wait and see.
***w00 3/15 p. 13 par. 12 ‘O God, Send Out Your Light’ ***
Just as the apostles understood many prophecies concerning the Messiah only after Jesus’ death and resurrection, Christians today understand Bible prophecy in its finest detail only after it has been fulfilled.