The sea zone is hostile. The transport must leave the sea zone in combat movement, unless other US units attack the destroyers. In any case, no units may be loaded there.
I know you need a destroyer in order for planes to attack them but you don’t need a destroyer for lets say your battleship to attack an enemy sub do you?
The UK and ANZAC are free to move any units into Dutch territories still under Dutch control at any time, but they may only take control of them with land units. The US is free to move any units into Dutch territories still under Dutch control only if it is at war, and it may never take control of them. Any power may attack Japanese-controlled Dutch territories and take control of them, as long as that power is at war with Japan.