Here is some information that will explain why the 1914 generation was dropped from the Awake masthead. This is from the Watchtower article, "Questions From Our Readers" dated June 1, 1997, pg. 28:
Questions From Our Readers
“The Watchtower" of November 1, 1995, focused on what Jesus said about "this generation" as we read Matthew 24:34. Does this mean that there is some question about whether God's kingdom was set up in heaven in 1914?
That discussion in TheWatchtower offered no change at all in our fundamental teaching about 1914. Jesus set out the sign to mark his presence in Kingdom power. We have ample evidence that this sign has been in course of fulfillment since 1914. The facts about wars, famines, plagues, earthquakes, and other evidences bear out that since 1914, Jesus has been active as King of God’s Kingdom. This indicates that since then we have been in the conclusion of the system of things.
What, then, was TheWatchtower clarifying? Well, the key was the sense in which Jesus used the word “generation” at Matthew 24:34. That passage reads: “Truly I say to you that this generation will by no means pass away until all these things occur.” What did Jesus mean by “generation,” both in his day and in ours?
Many scriptures confirm that Jesus did not use “generation” with regard to some small or distinct group, meaning only the Jewish leaders or only his loyal disciples. Rather, he used “generation” in condemning the masses of Jews who rejected him. Happily, though, individuals could do what the apostle Peter urged on the day of Pentecost, repent and “get saved from this crooked generation.”—Acts 2:40.
In that statement, Peter was clearly not being precise as to any fixed age or length of time, nor was he tying the “generation” to any certain date. He did not say that people should get saved from the generation that was born in the same year Jesus was or the generation that was born in 29 C.E. Peter was speaking about the unbelieving Jews of that period—some perhaps being rather young, others being older—who had been exposed to Jesus’ teaching, had seen or heard of his miracles, and had not accepted him as Messiah.
That evidently is how Peter understood Jesus’ use of “generation” when he and three other apostles were with Jesus on the Mount of Olives. According to Jesus’ prophetic statement, Jews of that period—basically, Jesus’ contemporaries—were going to experience or hear of wars, earthquakes, famines, and other evidences that the end of the Jewish system was near. In fact, that generation did not pass before the end came in 70 C.E.—Matthew 24:3-14, 34.
It must be acknowledged that we have not always taken Jesus’ words in that sense. There is a tendency for imperfect humans to want to be specific about the date when the end will come. Recall that even the apostles sought more specifics, asking: “Lord, are you restoring the kingdom to Israel atthistime?”—Acts 1:6.
With similar sincere intentions, God’s servants in modern times have tried to derive from what Jesus said about “generation” some clear time element calculated from 1914. For instance, one line of reasoning has been that a generation can be 70 or 80 years, made up of people old enough to grasp the significance of the first world war and other developments; thus we can calculate more or less how near the end is.
However well-meaning such thinking was, did it comply with the advice Jesus went on to give? Jesus said: “Concerning that day and hour nobody knows, neither the angels of the heavens nor the Son, but only the Father. . . . Keep on the watch, therefore, because you do not know on what day your Lord is coming.”—Matthew 24:36-42.
So the recent information in TheWatchtower about “this generation” did not change our understanding of what occurred in 1914. But it did give us a clearer grasp of Jesus’ use of the term “generation,” helping us to see that his usage was no basis for calculating—counting from 1914—how close to the end we are."