The hope is a bystander initiates CPR while waiting for the AED to arrive. No difference between waiting for a drone or waiting for the EMTs.
The new ACLS protocols coming put far less importance on rescue breathing and much more focus on the heart, keeping it pumping and the blood circulating. Each time you stop to breath, you loose circulatory pressure and it takes precious time to raise it again with chest compressions.
While you are correct, an average response time in the area I work in is approximately 15-20 minutes since the time of call. An AED getting on scene within 2-3 minutes would be beneficial. While I don't see a rural area implementing this due to high cost, I can see this happening some time down in the future.