This is a business and belief structure that can't stay stagnant in growth, it would financially implode.
To survive financially it needs constant new members.
Members provide two things, money and new members (ministry and having children).
Every young new member has the potential to supply decades of new members, with about half of their indoctrinated future children staying.
Older new members may leave the WT its finances especially with family distancing based on WT doctrine.
Watchtower know their stats inside out, hence all the data they collect from members. They know roughly how many hours ministry = x1 new member.
Bethelites, CO'S, Elders.... don't bring in new members. Pioneers tended to, just for statistical reasons. Watchtower know their business well and that sustaining it's position it is all about the hours of ministry!
Hence Pioneer privilege.....
But.....this will likely decline as 'the ministry' faces data and truth via the internet. Pioneers and ministry grind can't match an informed public.
I can see WT taking a 'new light' approach to ex members. A large source of potential new members. An 'all is forgiven' new light and new love bombing of long lost family and friends. I also can imagine a attempt to maintain retention by altering strict rules and making JW life a little easier.