It is a bit odd. I think the PCG authors are talking about reduced-round variants below 8[1] re: statistical quality. I agree it doesn't belong in a row labeled "ChaCha20." It seems obvious that chacha below 4 rounds is total garbage[2] but I don't know much about 4-7 rounds. The Too Much Crypto guy likes 8 rounds for cryptographic purposes.

[1]: https://www.pcg-random.org/other-rngs.html#id7

[2]: https://cr.yp.to/snuffle/diffusion.html