Beccabunny, I think the important thing to remember here is that the same GAC can be handled in different ways at the same attraction - and always has been. Your experience has never involved receiving a hand-written fastpass - however that has always been an accomodation that you COULD have been given. It depends on particular circumstances OF THE ATTRACTION, not necssarily of the guest. If providing a hand-written fastpass is the accomodation that is offered, you will need to have a "Plan B" to explain to your DD that the "wait" is on the bench or having a snack or a walk around before getting in line. I understand completely the need to manage expectations - we deal with the same thing. However, there are little times in life that even the expected doesn't work as we thought and we as parents sometimes have to be quick-thinking to turn a possible negative reaction (tantrum that she can't enter the ride RIGHT NOW) into a positive reactiion (oh wow, look, they will let us go get a snack before getting into line and we'll wait less! - the wait may or may not be less, but if presented to your child that way it could prevent meltdown).
There is no GAC that guarantees you will be allowed access to the ride - what if the ride is completely down at the moment - you can't just tell the CM "well my child expects to ride now so let us in line." A hand-written fastpass is similar, though you do have the alternative option to use stand-by if the handwritten fastpass is unacceptable.