It is certainly true that a node on the US902 plan cannot be used in Australia. However, is there any practical or legal reason why one could not use the AU915 Australian frequency plan in North America?
AU915: 915-928 MHz
US902: 902-928 MHz
The only difference between the two from my reading is the offset of the uplink channels as required by the ACMA. I am moving equipment between the two countries and therefore would prefer to avoid re-configuring the frequency plan where possible.
Presumably you would still need to perform the spurious emissions band edge tests at both 902MHz and 915MHz in order to achieve FCC Part 15 product compliance (see this forum post).