The PS2 had numerous sku's through out it's life. It didn't make a big deal until they brought out the "slim" version that people paid attention.
There are things that they could have done to reduce costs and change up the motherboards which will require a new FCC license to sell that unit. Once it's approved they cannot go and just swap different parts out for something less expensive, even if it's the same type of part but a different model # on it.
We pay much closer attention to this now because of all the accessibility that we can get off the net as well as people who closely monitor things like this so they can pass it off as news.
My pokemon brings all the nerds to the yard. And they're like, "You wanna trade cards?" Damn right, I wanna trade cards. I'll trade this, but not my charizard.