Disney contracts with BAGS, Inc. to provide Resort Airline Check-in. The good news is that AirTran is already on the
BAGS, Inc. website as participating airline (and AirTran has been there for several months). Unfortunately for AirTran passengers flying to Orlando, AirTran is still not on Disney's list.
Those of us who aren't directly involved can only speculate about the reasons for the delay.
You can write the three businesses that are involved Disney, AirTran, and BAGS, Inc. but I don't know how much good it will do. The answer is no until the answer becomes yes.