Quite recently, an ADFA/RMC-D graduate duxed his Army class at BFTS, Tamworth. He went to 2FTS and Hawks, all while wearing green. Unfortunately he didn't make the cut and he went back to Army Aviation, where he's done very well. An unusual case indeed, but recent proof it can and does happen.
To answer the OP's question - anything can happen if you perform exceptionally well enough and Service needs are there. Past instances are definitely not indicators that it will happen again in the future. In its most simplistic form, your best bet is: If you want FJ, go RAAF. If you want RW, go RAN or Army.