WT never said outright that "the end" would come in 1975 but the literature and thinking circa 1975 implied that if it did it, the event would converge with Bible chronology; but the wt also concurrently published in the ASI book that the time of creation of Eve and the end of 6th Creative day was an unknown variable that was a factor affecting any conclusions about 1975. The wt has not backed away from 1975 as the 6000th year from the creation of Adam; wt still stands on the date, and if the 7th creative day is 7000 years in length, it would fit if the Millennium would start 6000 years after the end of the 6th creative day -so that 6000 years of evil + 1000 years of restoration and killing death ("death where is thy sting?") God can finally proclaim the 7th day as GOOD, same as he did with all the other creative days. It fits nicely IF wt chronology is correct. According to Genesis we are still living in the 7th day of Creation (7th day is God's rest day.) 6000 years + 1000 years= 7000 years= 7th Creative day= God's day of rest.
-But wt never outright proclaimed that 1975 would in fact be the end. I never recall that.