Not all speculation,

It's accepted fact that the passenger isn't paying any of the cost. The "market price" to the passenger is $10-$20 for RAC.
The only reason for "speculation" is wondering if airline's financial participation is the reason more airlines don't participate. A poster who claimed to have negotiated with BAGS said BAGS normally pays rent to the facility hosting them and the airlines pay approximately the same money that they would be paying if the passenger used curb side check in. We have no way of knowing if that's true but it makes some sense.
I agree the date is "set in quick-sand". It's not known how the computer programming is going. My guess is the first notice we'll get is that SW is being tested "pilot program".
Previous poster, the "control freak" should only take carry on luggage. The airline is far more likely to misdirect your luggage than DME. DME gets backed up and you'll get your luggage an hour or two later. The airline misdirects your bag and you might not get it until the next day.