They're delisting in regions without PSN. The irony of Helldivers is they backpedaled on PSN requirement but left it delisted in those countries. So people who already bought it can still play but new people can't buy, so the player base is steadily declining.

Yeah, the previous Sony games on PC can be bought anywhere in the world but in Russia, yet the latest cannot be purchased in 170 countries, including some EU members like Estonia and Lithuania.