I don't know if more people are leaving. I think it is a different demographic that is leaving.
Growing up in the 70s and 80s I recall those who left were mostly teens and "spiritually weak" ones.
I only remember one elder ever leaving the Borg while I was in and it was right around the 1980 apostasy-purge period.
I was frankly shocked to see ANY elders here when I first joined the board but we're seeing elders and MS joining here all the time. The Borg was content with losing "weak" ones because they were easily replaced with born-ins and converts. Plus, those weak ones sometimes come back whenever there's a war or earthquake or hurricane or new disease found (Emotion control - FEAR). But now the Borg is hemmoraging their best and brightest. Even the elders who don't leave the organization or join JWN are often stepping down, putting further burden on middle management. The headquarters has to be approaching panic mode and don't dare alienate any more thinking JWs. The overlap was an insult to everyone's intelligence last year and I just don't think they have the balls to try anything else like it again just now.
Why else cancel the book release for this summer and drop whatever explanation they were going to float about the toes of the image?