As of now, this question of governmental funds being spent in juniors to develop Australian citizens of South Sudanese does not apply to the likes of Thon, Acuil, Deng Adel, Jackson Makoi, and many of these South Sudanese basketballers.
The successful South Sudanese players exit Australia as juniors and either play HS/AAU basketball and or college basketball in the US. They are not really resourced by Australia and are not really fully recruited by the Australian basketball elite pathway as they are in the US.
Thon, Deng Adel, Jackson Makoi, Mangok Mathiang, Makur Maker all played hs basketball in the US. The real question is what are the realistic opportunities to represent Australia when South Sudanese like Thon put their hands up and are deemed "not good enough" to play for Australia? I think young South Sudanese players are beginning to recognise that their talent are more appreciated elsewhere and therefore leave and find better opportunities.
If you really think about it, it took Thon getting drafted in the NBA for Australia to really even begin to open doors in their associations.