So kudo to the insurance for getting the back of the exchange users who have balance in their accounts before the crisis.
I don't think this is based on the Japanese license policy; it might also be part of it, but I strongly believe it's just part of the insurance policy and agreement that is being reached between the client and the insurance company. Maybe the insurance was openly listed that it's all to be used in paying back all their Japanese investors and customers if the exchange ever experienced any form of attack or filed bankruptcy; those funds deposited in the insurance account should be used to repay their customers.
The US customer and other countries are not under the same insurance; the exchange is insured, but the terms are different. I believe those in the US and other regions hope to recover their lost and misused funds on the exchange. Their insurance didn't cover up the customers deposits, but it's only their responsibility to cover up for their investors, whose investment safety is always their primary priority more than that of the customers who are making that money for them.