That is usually how it goes, Japan gets more releases than we do. In this case it seems the US PS2 players got the better version without being nicke land dimed to death.
Remember Capcom with Street Fighter 2 on SNES and Genesis? $50+ for expansions over and over. That sucked because at the time, tech was available to do expansion packs with cartridges, just look at Sonic and Knuckles. Maybe the fundamental code of the first SF2 on SNES was not programmed with this idea in mind or something, and I am sure it is much harder than it sounds to do an expansion that big on cartridge.