That maps showing relative abundance, so if there were four left in the world, all the map says is that they would most likely be found in the red zones, but may be in the yellow.
I think the rarity part of the statement is for anglers more than anything. They are large, solitary, palegic ocean fish that eat jellyfish. For those reasons, people probably barely ever hook them. I've been fishing the Gulf off of Texas my whole life and have never caught one, let alone heard of one. So if I hooked one, it would definitely be rare to me. I've also worked with endangered riverine fish that are endangered and "rare," but are thicker than fleas on a dog's back if you know where to look...
