They won't. When will they ever back down on a position? To reinstate the bookstudy would be to admit they were wrong to disband it. They'll never admit they're wrong. If they do, it will take a generation (not an overlapping one though) so everyone's forgotten about it. To reinstate the bookstudy would put them in a,position where they might lose face. We know they'll never inadvertently do that.
Besides, like some have mentioned they don't seem to have enough elders. My last congregation had to import elders from interstate sometimes. I reckon there will be lots of elders shunted all around their respective countries because they just aren't getting enough locally in a lot of places. After all, it's a dog's job.