Nick here from Shopify.
You are definitely correct in saying that Shopify is partnered with Worldpay which you can see here.
I reached out to the financial services support team at Shopify about this and they mentioned that your best bet is to reach out to Worldpay directly about this. It is something which is out of Shopify's control because Worldpay is a third party payment gateway independent of Shopify. Only they would be able to answer why Israel isn't showing up for you here. You can find the Worldpay support website here.
Hope this helps!
All the best, Nick