You're kidding, right? We got Dimension Fusion, the card that made that no longer true, the same set as Chaos Sorcerer. I guess technically the OCG got Chaos Sorcerer slightly before it, though. And technically either way Miracle Dig existed before either.
That's never been the case and I've been playinf since before most players lol. Just go back to DM and see that there were cards still there that made this not true.