The difference is that Helldivers 2 was already a released game; people had paid for a product which was going to be taken away from them. After all the controversy, Sony decided not to follow through with that plan and let people keep what they already had.
This is still scummy, but with Ghost of Tsushima, no one has received anything yet. People put in an order, the order was canceled, and money refunded, so in practical terms there is no loss...other than not being able to buy the game.
It may be possible to set your account to a different region and purchase anyways, but in my opinion, piracy is absolutely justified in this case when the vendor literally refuses to make a product available to you. If there's no legal option for obtaining it, then there's no harm in pirating it.