They say that they never said that about 1975. They deny it. They came out later and said something to the effect of “you guys got this crazy thing in your head and ran with it”, blaming the average member for running with what they had said.
They never came right out and said that 1975 would be the end. They just used things that pointed to 1975 over and over in books and then later edited out any reference to the year in a revision that came out years after it. They also believed that 1975 was the end of the first 6000 years of human history so therefore the seventh creative day (they see each day as 1000 years), the day of God’s rest, would originate in 1975 and usher in that 1000 year paradise that they believe in, starting with Armageddon destroying this world as we know it.
They also encouraged couples not to have children, with the end so close. They invited people to give up their worldly possessions to focus on the preaching work for the end that was so near at hand. There was a saying, “stay alive until '75”, because they wanted to make sure they saw the end of this world.
The organization known as Jehovah’s Witnesses is a master at saying things without saying them. Two years ago in 2014 they announced that it was the 100 year anniversary of 1914, the year that they think coincides with Christ taking his position as king in heaven, just waiting to lead the angels to wipe this earth of those not willing to serve God acceptably. In the Kingdom Ministry monthly leaflet that goes out to every member of the organization, when announcing the date for that year’s Memorial celebration (their observance of Christ’s death and resurrection), they asked the noteworthy question that got everyone speculating, and I’ll paraphrase:
Could this Memorial be our last?
In other words, they were hinting that with it being the 100 year anniversary of 1914, this might be a great time for Christ to come and bring Armageddon against this world, delivering us from it into paradise. You’ll note that they didn’t ever say it, they just recklessly hinted at it and with a membership full of people instructed to always be looking for signs of the end coming, they took it as a sign. It is masterful manipulation.
If you’d like to learn more about the 1975 cover-up, here’s a link to some people discussing it:
https://www.jehovahs-witness.com/topic/174077/1975-coverup-compare-68-81-truth-book-scans?page=1&size=20
You will see there scanned copies of books that they altered after the fact. You’ll see quotes that occurred years later as they built a narrative pointing to 1975, knowing that they had a captive group that was looking for the end. It is a remarkable foray into the world of manipulation.
Jehovah’s Witnesses are the proverbial boy that cried wolf. Somehow they keep their members looking for the same thing over and over, never disappointed, always blaming themselves if they were disappointed. JW’s have been predicting the end of the world since the late 1800’s. They continue to this day. There have been specific dates pointed to during this time. Even without that, they are constantly on the watch.