Sorry, but that is not longer the case.
Let’s go through this once again.
There are 3 (three) terminals:
1. The premium terminal. (Only for passengers in business or first)
2. The departure/transfer terminal.
3. The arrivals terminal. (For
all passengers entering Doha)
There will be separate busses for Economy passengers and for Business/First passengers picking you up at the airplane.
Depending on the parking stand of the aircraft, the routing will be different. E.G. if the aircraft is parked on the east side of the airport the arrivals terminal will be the first stop because this terminal is the nearest from the plane.
Normally, unless you have a very tight connection, this applies:
If you are in
economy the bus will go to two terminals, Arrivals and Departure/transfer. Not necessarily in this order as stated above.
In
business/first the bus will take you to Arrivals and to the Premium terminal.
Only if you are entering Doha you get out of the bus at the Arrivals terminal.
As long as you know whether you are transferring or entering Doha, it's not hard to understand at what terminal you should leave the bus.