One potential scenario is that DroneShield have just secured a...

One potential scenario is that DroneShield have just secured a military contract and the capital raising will be a direct injection of cash from a military to supply equipment.
This fits nicely within the timing of the US demonstration and explains why if a contract has indeed been secured, us small holders didn’t hear about it first. However I’m not aware of the restrictions around a foreign government agency securing shares in a small Australian equity.
However, due to national security concerns, if I’m correct all we may hear about is the number of shares offered and at what price.

All the above is IMO and speculation.