Compare:
"...forwarding research material, verses extracted for Bible study, or answers to use at congregation meetings would detract from the value of each individual’s personal preparation."--The Watchtower, October 15, 2015, p. 31
With:
"... in Jehovah’s organization it is not necessary to spend a lot of time and energy in research, for there are brothers in the organization who are assigned to do that very thing, to help you who do not have so much time for this, these preparing the good material in The Watchtower and other publications of the Society."--The Watchtower, June 1, 1967, p. 338
Translates as:
It's perfectly okay for "brothers in the organization" to forward research material, verses extracted for Bible study, or answers to use at congregation meetings if they are handpicked by Watchtower to do this, but if other "brothers in the organization" forward research material, verses extracted for Bible study, or answers to use at congregation meetings it would detract from the value of each individual’s personal preparation.