Your concerns are well founded.Can't speak for SYD but at PER where the new system has been on trial for a couple of months the new check in system has reduced the number of face to face staff considerably. Where before at peak times I would estimate approx 8 - 12 check in staff operating, there are now only approx four (that I could see ) and they where assisting pax learn the ins and outs of the self serve system and assisting little old ladies .I would be surprised if the new system , once the inevitable teehing problems are sorted would support a permanent number of four operators. My guess would be 2 doing the work previously done by 8-12.