It did. But if it hadn't been bundled with D20 it would have had as much impact as, say, the Fudge license. I would also argue that the d20STL helped a bit there as well.
Just for my clarity, perhaps - I am reading this (creation of the OGL) as shorthand for creating the OGL and releasing what became the 3.0 SRD. Open licenses released prior to the OGL didn't have much impact...
I would say that it all depends on how you feel about PI. If you think being able to declare PI ( even if potentially abused ) is a valuable thing, then the CC licenses are problematic.