I find this hard to believe, the WTS itself quotes from various bible translations when it suits them. Here's one of 9 times just from the NIV in the 2009 WT.
*** w09 2/1 p. 4 Who Is God? ***So the key to knowing God is found in the teachings of Jesus Christ, the Son of God. In fact, Jesus promises us: “If you hold to my teaching, you are really my disciples. Then you will know the truth, and the truth will set you free.”—John 8:31, 32, The Holy Bible—New International Version.