My understanding is the WT did respond only to BOEs and only if that BOE initiated the query to WT headquarters. No letter has ever been read to the cong. in general that I have heard of firsthand. WT never freely volunteered information about the NGO scandal, as that would be close to transparency for WT's tastes.
And, predictably, the few BOE's that did enquire about it and received a letter from WT, the explanation/answer/B.S. was completely dishonest. In other words, A BIG FAT LIE !
( I know this because I talked with an elder who's BOE did receive a letter...and the "explanation" WT gave was pure, unadulterated bovine residue).
BTW- I doubt 99.9% of JWs have a clue about this issue. WT is very good at hiding the truth...and JWs are very good at voluntary ignorance.