What happens when the Chinese hacker breaks in via the uplink?
Are all the circuit boards and chips it uses made in Australia or China?
Are we closing in on pilotless commercial flights?
Any thoughts?

All I can tell you is the military pays a LOT of attention to encryption and other IA issues (tampering etc.). Also, these vehicles will be partially autonomous, accepting high-level commands like attack that target and then attacking and reforming without further communication.
One interesting idea is line of sight optical comms, those are pretty well impossible to spoof.
Many of the ICs are doubtless made in Taiwan, although it behooves both Australia and the US to encourage native state of the art fabs.