Just a thought, but maybe the plan is to discontinue the yearly service reports. Just report the number who are baptized. The average JW also notices how low the increases have been over the last 10 years and it is discouraging to them. By saying that the preaching work is over, they will have no need to report all those figures, and the decreases will be masked. Actually, they could then start just counting the baptized and show an larger increase. They could spin it that JWs will never stop talking about Jehovah (using Jerimiah as an example of how the good news is like a fire), so the increase could said to be coming from the "informal" work.
That's probably not what they're thinking, but it is fun to speculate.