I'm guessing they're not counting 3D chips without hardware transform & lighting support (where the 1999 GeForce 256 was the first) as "GPUs". Also, 3Dfx got taken over by nVidia soon after, so I guess it's not completely wrong. Also... press releases aren't exactly the best place to look for unbiased information.
Yeah, I was a Gamer back then and the Voodoo series were called "3D Accelerators". NVidia coined the term "GPU" for the first GeForce.