It's stupid to release true current-gen titles on the PS2, because that means that you either have a last gen game, or you're "dumbing down" the game anyways so that the PS2 can handle it. But financially, it's still beneficial to release games on the PS2, because it has such high saturation, and plenty of people still don't have any current gen consoles.
It's especially beneficial to release on the PS2 when you have weight to throw around. What I mean by that is money and a name. Star Wars is a franchise that will sell so well no matter what, that they can be pretty much guaranteed to make a profit on whatever system they sell it for, so naturally they try to sell it for as many systems as possible. Look at Lego Star Wars II, that came out on practically every system imaginable. Less secure names, and companies that can't afford to spend that much can't really afford to spend/risk time or money on lesser platforms.
But don't worry about the quality of the real versions on account of the other versions. The other versions, including the PS2 one, are being developed by an entirely different company. Those versions will be limited, but the real ones won't be making those sacrifices.
God is a placebo with nasty side effects.