The WTS no longer uses the term "new light." Instead they call them "clarifications." Can find them on Watchtower Online Library Index under "clarifications" or "adjustments to understanding." (Remember, I am reporting not supporting WTS teachings). https://jwfacts.com/watchtower/directed-by-holy-spirit.php "Since the Governing Body claims not to be inspired, where does "New Light" come from? If not from God, why should anyone listen to them?
In retrospect, Watchtower mistakes are justified in the most pleasant way.
"The increasing light on God's Word as well as the facts of history have repeatedly required that adjustments of one kind or another be made down to the very present time. But let us never forget that the motives of this "slave" were always pure, unselfish; at all times it has been well-meaning. For those who truly love God's law there is no stumbling block." Watchtower 1979 Mar. 1 pp. 23-24
When not justifying errors, the message is quite different. To disagree with these admittedly "fallible" teachings is to be disloyal to Jehovah himself, leading to destruction.
"One observer noted that these men "were critical of the articles in The Watchtower, not wanting to accept it as . . . God's channel of truth, always trying to influence others in their way of thinking." However, loyal elders never try to influence others to reject any of the spiritual food provided by God through the faithful slave. As Jehovah's dedicated Witnesses, all of us must be loyal to him and to his organization. We should never even contemplate turning aside from God's wonderful light, pursuing an apostate course that can lead to spiritual death now and eventual destruction." Watchtower 1992 Nov 15 pp. 19-20 Serve Jehovah Loyally