Actually there was some kind of an apology...
In modern times such eagerness, commendable in itself, has led to attempts at setting dates for the desired liberation from the suffering and troubles that are the lot of persons throughout the earth. With the appearance of the book Life Everlasting—in Freedom of the Sons of God, and its comments as to how appropriate it would be for the millennial reign of Christ to parallel the seventh millennium of man’s existence, considerable expectation was aroused regarding the year 1975. There were statements made then, and thereafter, stressing that this was only a possibility. Unfortunately, however, along with such cautionary information, there were other statements published that implied that such realization of hopes by that year was more of a probability than a mere possibility. It is to be regretted that these latter statements apparently overshadowed the cautionary ones and contributed to a buildup of the expectation already initiated.
In its issue of July 15, 1976, The Watchtower, commenting on the inadvisability of setting our sights on a certain date, stated: “If anyone has been disappointed through not following this line of thought, he should now concentrate on adjusting his viewpoint, seeing that it was not the word of God that failed or deceived him and brought disappointment, but that his own understanding was based on wrong premises.” In saying “anyone,” The Watchtower included all disappointed ones of Jehovah’s Witnesses, hence including persons having to do with the publication of the information that contributed to the buildup of hopes centered on that date.
Watchtower 3/15/1980, pg.17