The site speculates NVIDIA is cooking up Ultra Quality because AMD's highest-quality FSR setting uses an upsampling factor of 1.3x, while NVIDIA's current Quality setting uses 1.5x upsampling. At least on paper, this could result in better image quality for FSR. It's hard to know because at this point in time, there's not a single video game that supports both AMD FSR and NVIDIA DLSS.
It would seem that Ultra Quality could be a response to AMD’s FidelityFX Super Resolution, which already offers a setting carrying exactly such a name. In this FSR mode game is rendered at 77% resolution, which could theoretically provide an upper hand to FSR if both technologies were to be compared side by side. Unfortunately though since FSR has been released not a single game has received support for both super-resolution technologies which would allow such a comparison.It's unknown when NVIDIA plans to release Ultra Quality mode but it's already present in the UE5 engine.