I think it is possible that the GB has realized that it is very easy for a publisher to be virtually inactive but reporting good hours. Only by having the publishers show up and go out in the not-"Bible-based" D2D work can the shepherds be certain the aren't being lied to.
They fail to grasp that a person could use the D@D as a mild fitness routine and never ring any doorbells, or use the opportunity to discuss anything other than the "good news" while at the door.
In short, the attitude of "You want me to go through the motioons? OK, I'll go through the motions" will increase, because the GB has completely removed the basis for ant feeling of "urgency" about D2D work; they have cut their organizational throat.