The WTS will outlive me even if I lived until 2080.
They may have less and less over time but there are plenty enough people and assets to keep them going a good, long while.
I don't even see the continued absence of Armageddon stopping them. They will find a way of explaining it away and human psychology will keep people bound to them.
The only hope is that more people will be brave enough to explore their doubts. There might be a critical mass of scandal around child abuse but even then the organisation has enough of a hold to keep people bound to them for years.