Watchtower 4/1/87
As the Mediator between Jehovah God and those who have been taken into the new covenant, he has been serving indeed as a wonderful counselor for these past 19 centuries. Now, since 1935, "a great crowd" of his "other sheep" has been taking in his wonderful counsel and is getting the finest instruction and guidance
WT 4/1/81
Why is that true? It is because the Founder of the celebration set it up for observance by those with whom he made a covenant for the heavenly kingdom. Although dedicated and baptized, those of the "great crowd" recognize that they have not been taken into that covenant for the Kingdom. They are not spiritual Israelites, forasmuch as they have not been taken into the "new covenant," which is made with spiritual Israelites through the Mediator Jesus Christ
WT 4/1/79
The new covenant will terminate with the glorification of the remnant who are today in that covenant mediated by Christ. The "great crowd" of "other sheep" that is forming today is not in that new covenant
WT 4/1/73
As Mediator, Christ also helps those in the new covenant to fulfill its terms and to qualify to be kings and priests with him. However, not all attending this memorial observance are partakers of the emblems served. However.Jesus said: "I have other sheep, which are not of this fold [of the "little flock"]; those also I must bring, and they will listen to my voice, and they will become one flock, one shepherd." (John 10:16) They would support the stand the anointed ones have taken and would cooperate in preaching the good news to others. But God has not held out the heavenly invitation to them,
The Watchtowers of 2/15/66 and 11/15/72 give the direct impression that Jesus is mediator for all.
So, it appears from the pages of the Watchtower the change took place ON paper in 1972/1973.
This is what it says in Crises of Conscience (1999 edition, pages 270-271)
(November 16, 1979), the Societys president, Fred Franz, was presiding at the morning Bible text discussionhe stated that some were questioning the Societys position (set forth in a recent Watchtower) that Jesus Christ is the mediator only for the "anointed" ones and not for the other millions of Jehovahs Witnesses. He said of such ones: "They would merge everyone together and make Jesus Christ the mediator for every Tom, Dick, and Harry."
for me it was evident from Scripture that Jesus Christ did ofer his mediation to bring about reconciliation with God for every Tom, Dick, and Harry
Thanks Ray Franz!!!!!!!