Maybe giving preference to S/X drivers so they have a few super chargers extra spots per location over 3 drivers?
Hmm, not sure how, since the new ones are dual cabled.. so converting all of them wouldn't affect availability for S/X drivers in any way?
I haven't seen the "Model 3 priority" stickers on any of the photos of Australia stalls, so to me it seems reasonable that they expect all stalls at each site to be done by the time Model 3s are here and ready to use them.
[Edit: My images weren't loading before and I didn't see the winky face!!]